Shouting at the ocean with pebbles in my mouth since 2008. The subjects of this blog include forensics, the war-on-terror detainees, the Duke lacrosse case, the Knox/Sollecito case, and the academic world as it intersects the political. It will sometimes examine issues of particular interest to Wilmington, NC and the University of North Carolina at Wilmington.

Tuesday, July 30, 2013

An interview with David Balding

Part 36 in the Knox/Sollecito case

Professor David Balding recently published an analysis of the bra clasp DNA. It may be helpful to explain some terms found in this article. John Butler (Fundamentals of Forensic DNA Typing) defines the
liklihood ratio (LR) as “The ratio of the probabilities of the same event under
different hypotheses, and he explains that the prosecution’s hypothesis is
usually the numerator, and the defense’s hypothesis is usually the
denominator.A ban is a unit of
expressing the weight of evidence (WoE). This scale is logarithmic; a likelihood ratio of three bans is
equal to one thousand. Some months ago Dr. Balding was kind enough to answer some of my questions about this work.

Does Raffaele Sollecito¹s
DNA fall into the category of low template DNA,

and if so, should two
separate amplifications have been run?

There's no strict definition
of "low-template" but broadly yes the peaks associated with Sollecito
are low (but not those associated with Kercher, they are high).
Conti-Vecchiotti discuss a threshold of 50 rfu below which a peak should
not be relied on; in the UK, that threshold was used in the past but nowadays
as techniques have improved the threshold is often lower, 25 or 30.
However that doesn't matter here as all the peaks associated with
Sollecito are well above 50: there is a 65, a 70 and a 98, all the 26 other
peaks are above 100. So it is not extremely low template - many low-template
cases are successfully prosecuted in the UK even when some peaks fall below the
threshold and so are discounted. In this case all the peaks associated
with Sollecito seem clear and distinct so I think there can be no concern
about the quality of the result as far as it concerns him or Kercher.

Replication is generally a
good thing and is nowadays done in most cases in my experience, but not all -
one problem is that replication splits the sample and so can increase the
chance of not getting a usable result. But although replication is
desirable it is not essential. (In a sense there already is replication,
because each of the 15 loci is an independent test.) This is all a matter
of weight of evidence, which Conti-Vecchiotti paid no attention to: if you
measure the weight of evidence properly, that accounts for the extra assurance
that comes from replication and gives a stronger result (or conversely gives a
weaker result if there is not replication). But because Sollecito is
fully represented in the stain at 15 loci (we still only use 10 in the UK, so
15 is a lot), the evidence against him is strong even allowing for the
additional uncertainty due to non-replication.

Are there contributors other
than Raffaele Sollecito and Meredith Kercher to the autosomal profiles?
If so, how does the presence of this additional DNA affect the bra clasp
as evidence?

Yes, Conti-Vecchiotti
identified a further 12 above-threshold peaks at alleles that could not have
come from Sollecito or Kercher. They correctly criticised the scientific
police for ignoring these: many do appear to be stutter peaks which are usually
ignored, but 4 are not and definitely indicate DNA from another individual.
The extra peaks are all low, so the extra individuals contributed very
little DNA. That kind of extraneous DNA is routine in low-template work:
our environment is covered with DNA from breath and touch, including a lot of
fragmentary DNA from degraded cells that can show up in low-template analyses.
There is virtually no crime sample that doesn't have some environmental
DNA on it, from individuals not directly involved in the crime. This does
create additional uncertainty in the analysis because of the extra ambiguity
about the true profile of the contributor of interest, but as long as it is
correctly allowed for in the analysis there is no problem - it is completely
routine.

Are there contributors to
the Y-STR profile other than Raffaele Sollecito? If so, how does the presence
of this DNA affect our interpretation of the bra clasp as evidence?

I haven't looked closely at
the Y evidence - there seems no need for it because the autosomal evidence is
overwhelming for the presence of DNA from Sollecito. But from a look at
Conti-Vecchiotti, it seems to back up the conclusion from the autosomal
profiles: Sollecito's alleles are all represented and these generate the
highest peaks, but there are some low peaks not attributable to him; so at least
one of the additional contributors of low-level DNA to the sample was male.

The bra clasp was collected
about 47 days after the murder, and it was found in a different
location from where it was initially observed. In the interim many people
entered the cottage and items from her room were removed. Are these
concerns sufficient for the clasp to be excluded as

evidence?

The only worry would be if
somehow DNA from Sollecito was brought into the room and deposited on item
165B. I don't know enough about what happened to say if that was likely
but I'd guess that people walking in and out of the room etc would be unlikely
to do that.

The clasp was collected with
gloves that were not clean, not with disposable tweezers (videos here and here).
The glove was handled by more than one person. Are these concerns sufficient
for the clasp to be excluded as evidence? If not, should the clasp be
given less weight as evidence because of them?

Same comment - the only
concern is if any of this could have transferred DNA from Sollecito onto item
165B.

Would you care to comment on
the storage of the clasp after the forensic police tested it?

I know nothing about it.

Did you analyze the
electronic data files? Did you examine the laboratory¹s own protocols and
machine logs?

I have only seen the epgs
for the autosomal DNA profiles of 165B. There is an unclear version of
them in the Conti-Vecchiotti report, but Prof Vecchiotti kindly provided my
with a clean set.

124 comments:

Anonymous
said...

Chris, have you correlated the time that the cottage mop (the one taken to Sollecito's flat and returned) was taken into the murder room (see YouTube "Stefanoni gift wraps a mop") with the time that the "swept up" bra hook was found partially beneath a small rug in that room? Have you considered how and with what that "sweeping" was accomplished?

Some of my views can be inferred from my questions, but let me expand upon one point. The decay of the bra clasp is additional evidence of the incompetence of the forensic investigators. I tend to agree with one lawyer who said that when an item of evidence goes missing or is allowed to decay, the court should be obliged to accept the defense's interpretation of the item. If the clasp had been stored correctly, it might have turned up additional evidence of contamination.

Interesting! It doesn't surprise me that further analysis of the electropherograms indicated that Raffaele contributed DNA to the bra clasp, what's intriguing is that he analyzed for Amanda's DNA as well. That wasn't something I was expecting to read when I began his paper, but it didn't surprise me he found little support for it!

I wonder how close he's been paying attention to the case? The paper and the answers to queries suggest he thought the issue was a statistical one regarding a mixed sample and that Raffaele's contribution was in dispute. His answers to the contamination questions shout that out, as just about everyone expected that Raffaele's DNA got on the clasp (or in the sample of the clasp), therefore any contamination contributing to that result would have likely have been introduced via his own DNA.

You are, in my opinion, slightly misrepresenting the court's claim for proof of contamination.Essentially, the problem here, as the court sees it, is what is to stop defence lawyers advancing contamination claims in any murder case. A clear path, even if not proven, must be demonstrated to support such claims. And it is rightly up to the defence to show this - not the prosecution. It really is basic common sense, and I doubt that any court in the world would disagree. In the Kercher case, the defence were permitted to have their own experts present with police proceedings at the cottage on video.

What interested me most about your interview, was Balding's laying to rest of the old contamination theory by several other males. He informs us that this environmental DNA is completely normal and routine. Frankly, it's shocking that such nonsense talk about the additional males was allowed to continue unchecked. Were you, as a scientist aware of this?

I also must congratulate you on having the balls to publish this, since you are a strong advocate of innocence, not that it proves anything one way or another.

There are a number of problems with what you said about contamination. One, it is not the defense but the independent experts who pointed to contamination. Two, the ISC motivations document speaks of the "unproven hypothesis" of contamination. It also states, "Professor Novelli said that the origin, the vehicle of contamination must be demonstrated..." Thus the ISC is demanding proof. Three, the problems with the DNA evidence in this case do not occur in every case: one hopes that not every crew of forensic technicians flouts basic collection protocols as boldly as the one in question did, and no one has ever satisfactorily explained how a knife can be cleaned of blood yet not DNA.

I am not sure what you mean by a clear path, but there are several routes by which Sollecito’s putative DNA could have arrived on the clasp. In a previous I entry here I dealt with the erroneous belief that observing the collection of evidence or observing testing of items suffices to ensure that everything was done properly; briefly, the defense must have access to the electronic data files, as well as other forensic information.

Professor Balding said that he did not examine the YSTR data closely but thought that at least one additional contributor was male. Having just now reexamined the YSTR electropherogram, I would say that there are at least two additional male contributors. With respect to both the autosomal and YSTR data, the same thing is true: the existence of DNA rarely gives information on the time or manner of its deposition. It is dubious to do so on the basis of peak heights, but in the case of the autosomal profile, the peaks from the additional donors are much closer in size to Raffaele’s putative profile than either are close in size to Meredith’s.

Moreover, the forensic police should have obtained substrate controls in the vicinity of the clasp. As Conti and Vecchiotti said, "The item was recovered 46 days after the crime, in a context highly suggestive of environmental contamination. The risk of incorrectly interpreting such environmental contaminants from dust could have been minimized only by taking the care [avendo l'accortezza] to institute extremely stringent control procedures, including the analysis of extracts from sterile cotton swabs soaked with sterile buffer passed on ambient surfaces to take samples of dust, a procedure which was not carried out..."

To my knowledge, the defence were trying to raise contamination issues long before C and V. This would be common policy in most murder cases with forensic evidence involved. Relying on C and V seems pointless, the Supreme Court did not seem too impressed with them. It's a bit like arguing guilt because Massei and Micheli said so.

True, the court speaks about the unproven hypothesis of contamination, and Novelli said the origin or path of contamination must be demonstrated, and that makes sense. If you don't have these parameters, what is to stop any defence lawyer claiming contamination? You claim that in this particular case the forensic work was terrible. I don't know - I have no experience of that. I do know a video recording was made, and it would seem strange that police forensic officers happily recorded themselves breaking all protocols. For that, just as Balding provided us with his views re. the clasp DNA, so perhaps we could solicit the views of other police forensic units.I don't think you can be serious about how a knife can be cleaned of blood but not DNA - if there is DNA on the blade, that speaks for itself.There is really nothing new in all of this, as I said before, what struck me most, was the laying to rest by Balding of several male contributors to the bra clasp DNA. He states that this environmental DNA is routine with every crime scene, and that the origin of at least one contributor was male. You say you can now make out two. On the threads of IIP posters were claiming up to six. I only came across this information once before in an article. Of all the threads I read on the pro guilt and pro innocence sites, the only poster to have got this right was Machiavelli/Yummi. Certainly, I don't think the pro guilt sites knew any better. I take it that you don't agree with Balding, and that's OK, we all have our point of view. Frankly, I'm a little concerned that after all the hyperbole over this case from various consultants and experts, an everyday forensics professor has to enlighten us. I think that teaches us that we should solicit the views of those people directly involved within the various professions concerning this case - real forensic crime scene officers, real police detectives.

I have reexamined the YSTR electropherogram. If one takes 30 RFU as a cutoff, there are three contributors besides Sollecito's putative profile. The minor peaks are distinct and not in stutter positions relative to the largest peak. One locus had six called peaks above 10 RFU plus one distinct peak that was not called. Therefore, two additional male contributors is only a lower bound on the number of profiles.

Dr. Balding wrote, "After reclassifying as uncertain all peaks below 15% of the height at one extra repeat unit, a common stutter guideline (4)..." With respect to the stutter in the autosomal profile, one can obtain information about the ratios on p. 125 of John Butler's 2005 textbook, Forensic DNA typing. Stutter increases as the number of repeats increases, and the percentage of stutter height to allele height depends on which locus is examined. In TH01, stutter peaks are less than 3%. Only for the longest number of repeats in D18S51 does the stutter get near 15%, and for the other alleles, it is less than or equal to 10%. Therefore, a cutoff of 15% might be generous.

"What would I accept as proof of contamination" - well thank God we are on your forum, otherwise I might have been asked for a timeline!

Look, the problem here is we have a bra clasp, and whose DNA is it contaminated with - the suspect. Then there is a knife, and whose DNA is the blade contaminated with - the victim. As a scientist, you must realize the odds here aren't that good, and you can't really blame people for talking meteorites. Then maybe you are suggesting deliberate contamination, and that is a whole different ball game. There I can see a reasoning, a path - no interrogation recordings , busted hard drives, shifting bra clasps, etc.

Gallagher you make an interesting point, but you seem not to realize that both the bra clasp and the knife are anomalous results and as such the question is how the DNA got into the sample rather than the DNA absolutely proves those items were touched by either party in the course of the murder.

The bra clasp is the only trace of either Raffaele or Amanda which was ever found in that room of the hundreds of items they sampled. They found Rudy Guede's traces inside Meredith, on her clothes, on her purse and on her wall, and his shoeprints all over the room. They initially found nothing of either Raffaele or Amanda, the bra clasp being found some six weeks later after they'd trashed the crime scene.

I'm sure you've seen the bra clasp collection video, have you ever wondered where the bed is? They'd taken out through that doorway where Raffaele had tried to break down the door. You can see in the crime scene videos technicians going in and out of that room, the bra clasp must be on the floor somewhere, in fact considering it appears intact and adhered to the bra in the initial videos directly after the discovery and all messed up when they 're-discovered' it six weeks later, someone probably stepped on it! Take a look at this video to get an idea of just how trashed they left that room and the changing condition of the clasp.

The knife was the only thing at Raffaele's that they could even try to connect to the murder. They went over that thoroughly as well, laid down luminol and got a number of hits--that turned out not to be blood. They took plenty of samples there,too, but what was the only thing from Raffaele's they got? The tiniest hit from an unquantified sample in which most of the 'peaks' were 20-40 RFUs. Being as that knife didn't match the wounds and tested negative for blood with different tests in plenty of locations (on the knife) at different times, that may well be the most obvious case of 'environmental contamination' in the history of crime! It could have been transfer (Amanda lived with Meredith!) it could have been contamination in the lab or handling, it could have been fraud, what it wasn't was the murder knife.

Forensically, fraud and 'environmental contamination' show up as the same thing, anomalous items that can't be corroborated with anything outside other fraudulent items or misinterpretations. There's reason to believe either (or both) may have happened with the bra clasp and knife, either scenario can be supported.

What's missing support is the bra clasp and knife being evidence that Amanda and Raffaele were in that room; the utter lack of anything found there and the dubious nature of both items and the speciousness and incongruity of what 'evidence' they did muster screams that out.

Why do you suppose two former FBI agents flew to Italy in order to assist the defense?

Gallagher, You wrote, "I do know a video recording was made, and it would seem strange that police forensic officers happily recorded themselves breaking all protocols." A number of protocols were broken, including but not limited to a failure to change gloves in an appropriate way (I may address this in a future entry). I don't think the video is so strange in one sense. If the forensic police know that the Court of Cassation will back them up regardless, then why should they make the effort to use good technique?

I spoke to a former police officer from a small city, whose job it was to secure crime scenes. I described the six-week interval and the foot traffic in the cottage, prior to the collection of the clasp. The first words out of his mouth were, "Contaminated, contaminated." Dr. Elizabeth Johnson and Professor Gregory Hampikian wrote, "Handling and movement of this sample has compromised its probative value. The laboratory results for this sample cannot reliably be interpreted to show that the DNA of Raffaele Sollecito was actually on the bra clasp at the time of Meredith Kercher’s murder, and it does not establish how or when this DNA was deposited or transferred." It is indeed important to seek out expert opinion in this matter.

Spare me the detail, I am acquainted with the case. You seem to want to grossly exaggerate police procedure at the cottage - trashing etc. It all amounts to the same thing. You are suggesting that somebody either trampled or handled the clasp, and that this same person had previous contact with Sollecito's DNA and subsequently transferred it to the clasp - hence contamination. Point is, that would be extremely unlikely

You also want to give the impression that Kercher's DNA on the blade is somehow imaginary because it is low template, when , in fact, there is confirmation from leading experts. If it does exist, then it is either contaminated or has been placed by fraud. The crime scene is restricted to the bedroom and exterior detail and evidence can be ignored.

In other words you are 100 per cent sure they are innocent, and anything contrary is either wrong, fabricated or imaginary. I like to give them the benefit of the doubt too, murder and sex games don't really gel with me, but I also like to keep an open mind and look at the evidence.

Chris,My point regarding the video was basically that if people record themselves you can generally rest assured they will not do much wrong. You know as well as I do that you could video brain surgery and there would still be room for criticism.

You may have noticed, you are on the front page over at True Justice. As usual people won't talk directly, so let me pop you the question - if you don't mind.

Why did you publish the Balding interview? Taking it a step further, I can't help but notice a slight bit of hypocrisy here. You had the courage to publish, yet as a scientist, you must have been aware that the extra male contributors were from environmental DNA or that the likelihood existed. Why have you never referred to this before? Chris, I won't be the slightest offended, if you tell me to mind my own business.

Professor Balding wrote, “Yes, Conti-Vecchiotti identified a further 12 above-threshold peaks at alleles that could not have come from Sollecito or Kercher. They correctly criticised the scientific police for ignoring these…” I agree with this. However, where I completely disagree is that anyone can tell which DNA comes from environmental contamination and which does not. It is just as thorny a problem as attempting to tell whether DNA has arrived via primary or secondary transfer. As Jason Gilder wrote, “One of the standard axioms of DNA typing is, the presence of a DNA profile says nothing about the time frame or the circumstances under which DNA was transferred to that item. Contamination falls into is one such instance of an issue that cannot be identified by the electropherogram alone (unless you are dealing with a control sample or other known profile).”

Consider the YSTR results first. There are up to five male contributors besides Mr. Sollecito. If their DNA arrived in a way that is unrelated to the crime, how can one make the claim that Mr. Sollecito’s DNA arrived differently? Yes, Mr. Sollecito’s putative profile is stronger than the other profiles, but there is no support in the literature for differentiating between primary transfer and other means if transfer via peak heights. This standard is even more problematic if one tries to apply it to the autosomal profile. There the peaks belonging to other individuals are almost as strong (and in at least one instance) stronger than the peaks attributed to Sollecito, as Professor Tagliabracci pointed out. Moreover, both Sollecito’s putative profile and the unknown donors’ profiles are far weaker than Ms. Kercher’s profile. How can that be, if both Sollecito’s DNA and Meredith’s DNA arrived via primary transfer? And that is not an exhaustive list of problems with the clasp.

I respect Professor Balding’s credentials in statistical genetics. However, I cannot make the case that he knows more about evidence handling and collection than Professors Conti and Vecchiotti, or the authors and co-signers of the 2009 open letter, which include Professor Hampkian, Professor Krane, Dr. Johnson, and Dr. Gilder. Quite the contrary. Their view of the clasp is that its evidentiary value is weak, at best. My study of DNA contamination events leads me to essentially the same conclusion. Moreover, I would be tempted to exclude the clasp profile as evidence on either of two grounds: One, it was taken up long after the commission of the crime, which goes against standards of DNA evidence collection. Two, it was not handled correctly when it was collected.

You have been fortunate enough to have been given the time of day by a highly reputed expert and you now do him the disservice of trying to undermine his findings.

When are the Knox supporters going to finally admit that one plus one equals two?

On so many points with this case, there is the logical, practical and forensic-friendly explanations versus the far fetched and highly unlikely excuses favoured by Knox fans.

For someone with your qualifications it is astounding that this doesn't embarrass you.

Seriously, Sollecito's DNA is on Meredith's bra clasp despite it's handling because he tried to get her bra off during the attack. There, that isn't difficult, is it?

The Knox's paid $1million plus to have their daughter's history rewritten and the facts of this murder distorted and bastardised. No one with any pride in themselves would ever help spread this rot and you should be ashamed of yourself.

Anon. at 7:44 AM. You wrote, "Sollecito's DNA is on Meredith's bra clasp despite it's handling because he tried to get her bra off during the attack." Your statement is unsupported. Did you not understand what Dr. Gilder wrote? Professor Balding wrote, "The only worry would be if somehow DNA from Sollecito was brought into the room and deposited on item 165B. I don't know enough about what happened to say if that was likely..." I am in broad agreement with his statement up to that point. The problem for the prosecution is that there are a number of possible routes by which Sollecito's might have arrived. These scenarios are interesting mental exercises, but the proof that the clasp is contaminated is found right in the egrams themselves, both the autosomal profile and the YSTR profile.

Anyone who denies the possibility of contamination through clothing, gloves, or other means should reconsider on the basis of the Lukis Anderson case, among others (Link 1 and Link 2 ). That contamination occurred in this murder investigation is not in dispute, but the route is still under investigation. Mr. Anderson faced a possible sentence of death if he had been convicted.

I know this interview was about DNA science and not the Italian police, but isn't by far the most probable explanation, if the DNA is Sollecito's, that a corrupt cop or cops put it there when they saw how bad their arrest of Knox and Sollecito made them look (after Guede was proven to be the culprit) and press attention was ramping up?

The bra clasp -- it's almost too perfect isn't it? I don't want to make light of this horrible crime but what young woman does not have memories of the time a young man reached for the bra clasp?

The jailing of the Italian reporter who criticized Mignini is all you need to know. In fact, I would look carefully to find out if the same cops have been involved in most of Mignini's abuses. He went after some police chief over there, so not all was approved by top brass. And the illegal wiretapping must have been done by some cops. Find out who was wiling to break the law in that, and see if they rounded up the bra clasp or has access to Sollecito.

An alternate theory I do not hear discussed, for those who believe the cops were honest:Sollecito and Guede murdered Kercher, Knox was not involved.

It's a ridiculous theory but forensically there is more support for it than Guede, Sollecito, and Knox acting together.

1. Knox and Sollecito smoke dope and have sex at his place. Knox passes out. 2. Sollecito goes to Knox' place. Maybe to spy on her, maybe to try to have sex with Meredith, (no roommates at home so it could all be on the DL) maybe to steal, does not exactly matter. *If you buy into the knife being a murder weapon, then Sollecito takes it home, cleans it up, (he thinks) and of course Knox' DNA is on it from the time she used it to make dinner for them. )3. Somehow, Sollecitor's visit turns into murder with Guede who comes by for whatever reason. Again, if you buy the knife being a weapon, or maybe the only weapon, then Sollecito brought it with him presumably to kill Kercher because he's a sicko. 4. Guede runs, Sollecito goes back and goes to bed, going to pretend he as asleep the whole time. Knox knows nothing.

I think this scenario goes better with the prosecution's theories that putting Knox in it, because of her absence of DNA in Kercher's bedroom and Sollecito's knife being used.

There are of course countless flaws in it, I am just saying they all seem to also apply to the theory Knox was involved.

I don't think Sollecito went back to the murder house, after the murder, seek the bra clasp in his hand, rubbed his hands against it to place his own dna on it, to make sure it's there. He was by the way in prison at that time. But, I guess in your mind all innocent people do this and all convicted murders are innocent, also Guede, who MUST have gone back, place his dna all over the place, even though he clearly is innocent according the same logic!A murder trial never relies on only ONE evidence anyway. There are so many other evidence , two eyewitnesses, (who OF COURSE are not reliable)and Guede who say Sollecito&Amanda were there.And Solecito's knife where Meredith's dna is on, in his home.

Gallagher, what I'm pointing out should be obvious if you think on it, and it's not just me saying it, Steve Moore a 25 year veteran of the FBI calls it the 'mountain of missing evidence.'

Where would you look for the best evidence of murder? The room the victim was murdered in! Did they have any problems finding evidence of Rudy Guede whose DNA has no business being in that room at all? No, as I detailed above they found it in numerous places at the crime scene when the true Polizia Scientifica did the forensic work. I showed you that video, doesn't it look like they trashed it? Do you know why? They were done with it! They'd finished their work and moved on to the next case.

The second trip out to the crime scene was the local (Perugian Polizia di Stato) cops who realized they didn't have evidence against Raffaele and Amanda, that may explain why they act like such clowns in the video. The independent court experts led the court through a laugh-a-thon as they showed them those videos and read from their own manual and then showed them not following it and doing precisely what they weren't supposed to. An Italian judge recently retired and amongst his criticisms of their justice system he included seeing what happened in that video as intolerable. You seem to think that video didn't cause them problems thus their conduct must have been OK, it just so happens you're wrong on both counts. :)

Just think it all the way through: if contamination was not a concern, why all the protocols and bunny suits? (that isn't forensic wear either it's hazmat) Why do they even bother with that if contaminating samples through transfer is such an unlikely event? Considering the Y-haplotype shows three different alleles at three different loci, you know that there were at least three male contributors to the clasp, lowering the threshold further you can find evidence of even more contributors. Do you think they all touched the clasp? That's doubtful, Rudy Guede isn't even one of the possible contributors also that bra was ripped off from the other side, there's no reason to think the bra clasp was even touched by anyone in the course of the murder.

As for thinking them innocent, that's not where I started, it's where I ended. I waded through every bit of the 'evidence' against Amanda and Raffaele and realized it was all mistaken, obviously misinterpreted or irrelevant, it's not that difficult to figure out actually.

Again, why do you think two former FBI agents flew to Italy to assist the defense? You mentioned the knife, I just read that the former head of the FBI DNA lab, Bruce Budowle started assisting the defense too, citing the knife not possibly being the murder weapon, which the numerous negative blood tests and the fact it didn't match the wounds ought to make obvious: any cleaning event that would scrub every last trace of blood (which is very difficult to get rid of) off the blade couldn't leave DNA as a residue, especially when traces of starch indicate it was never thoroughly cleaned in the first place.

The police in this case screwed the pooch bigtime by arresting three people before the forensics were complete. When they got got the results in they found no trace of any of the three people they'd arrested for a bizarro theory the prosecutor just made up, instead they found evidence of a local petty thief who'd fled the country. They then tried to pretend they'd been right all along (even though the 'evidence' they based the arrests turned out to be entirely irrelevant or mistaken) and threw every stupid little thing they could find against two of the remaining innocents. Otherwise they might have had to tell the press of three nations they'd gotten massive coverage from that they'd made a gross error and it was just what the real evidence suggests, a tragic but mundane interrupted burglary.

The prosecutor himself was under investigation and would later be convicted for a previous bizarro theory in which he'd arrested and charged twenty people in course of trying to pretend a local suicide from years back was really the work of a Satanic cabal that was responsible for the murders of a long inactive serial killer.

He's a publicity seeking loon, see if you can figure out how he's trying to deceive you. He has a group of a few dozen fans online, some of whom spend all day long lying and twisting everything in order to pretend his 'evidence' is still good, and his theory possible.

Anon. at 7:44 AM, You wrote, “On so many points with this case, there is the logical, practical and forensic-friendly explanations versus the far fetched and highly unlikely excuses favoured by Knox fans.” Nonsense. Kaosium and I are willing to talk about the forensics, but you and other pro-guilt commenters have repeatedly come up short when we get to specifics. Your comment about $1 million for history to be rewritten is so far out in left field as to discredit everything else you wrote.

Anon. at 11:55 PM, I think that secondary transfer, contamination, and tampering are all more likely than that the DNA arrived via primary transfer during the crime. To take just one example of missing evidence, if Raffaele restrained Meredith, then his DNA should be on her cuff or her wrist.

Anon. at 1:42 PM, The single strongest piece of evidence against Guede is his bloody handprint, not his DNA. In fact one could throw out all of the DNA evidence in this case, and there would still be enough to convict Guede twice over. With respect to the DNA on the clasp, the presence of DNA does not indicate how or when it arrived; that is a limitation of DNA evidence that is sometimes underappreciated.

Kaosium at 2:20 PM, “Just think it all the way through: if contamination was not a concern, why all the protocols and bunny suits? (that isn't forensic wear either it's hazmat) Why do they even bother with that if contaminating samples through transfer is such an unlikely event?” This is spot-on. The precautions are all designed to minimize the chances of finding DNA that is unrelated to the crime.

I took a fresh look at the YSTR results. At 50 RFU, there are at least two additional contributors to one locus in the YSTR profile (DYS390), besides Sollecito's putative profile. At 15 RFU there is at least one locus (DYS458) with three additional peaks besides the one attributed to Sollecito. In DYS391 there are four peaks above 10 RFU that are not in obvious stutter positions besides the main peak. There are also some peaks in several loci that are not called that look to be about 10-20 RFU. Even one additional profile significantly weakens the prosecution's case IMO, but I would put the actual number as between 2 and 4.

In DYS390 the largest peak is 401 RFU, the second largest is 107 RFU, and the third largest is 76 RFU. There is also a peak with RFU of 41 that is in a stutter position with respect to the 401 peak. The stutter ratios in YSTR are not identical to the stutter ratios in autosomal profiling, but let us assume that it is stutter for argument's sake. That means that there were two additional contributors, with one of them having a peak height that is almost 27% of the height of the main peak.

Your comments on JREF and IIP, are for the most part, at least from a pro innocence perspective, intelligent and readable. Now, here you are, for some reason best known to yourself, spouting gobblegook. One gets the distinct impression, your posts are more geared towards public consumption rather than sensible discussion. Which really leads to the question I was raising with Chris, namely, how far should bloggers/posters go with concealing or economizing truth and fact when advantageous to their respective sides. The complete polarization of opinion surrounding this case is so incredible that there is no room left for rational debate.

It is not so surprising that both camps are so bereft of genuine and impartial expert advice - they simply cannot stomach a contrary opinion. Balding did not make any extraordinary claims. He did not really even confirm the forensics were not contaminated. He simply confirmed that Sollecito's presence was strong and that the extra contributors were most likely environmental and routine.

Sollecito's putative profile was weak, with the peaks typically in the 200-300 RFU range. The statistical inference that it is his profile may be strong (Dr. Balding's point), but that is something different. Dr. Balding's claim that the extra alleles is a separate matter and rests on a different kind of evidence. I would like someone to define what environmental DNA is exactly, and to enunciate the general rules by which one tells environmental DNA from nonenvironmental DNA, preferably with a citations to the DNA forensic literature. Perhaps someone could also explain how such a rule would be compatible with the axiom that Jason Gilder presented and why (if such a rule could exist) do people use substrate controls.

I have never knowingly concealed anything, and I find your implications to that effect unwarranted and out of place. Moreover, you have answered questions and objections to your positions with deflections and (in one case) an invalid appeal to authority. None of these things is conducive to rational debate. Your actions speak more loudly than your words. If you want to have a rational debate, I would welcome it, but that is not the course you have set so far.

As we know, in a court of law the prosecution is responsible for proving the case beyond a reasonable doubt. This is why it should be up to the prosecution to show that the DNA was properly collected and tested and that the evidence is probative. To excuse the prosecution from this duty is to shift the burden of proof to the defendant. Surely, we can agree that this is not a good idea. It is an especially bad idea when videos available to the public demonstrate that the DNA collection methods did not begin to meet international protocols.

It's even worse when there is no sound corroborative evidence. Something is invariably and inexplicably odd about every single piece of pitiful evidence in this case. Why?

As for Mr. Balding, perhaps he has his own prejudices to deal with in this case. Maybe he prefers to believe the DNA can unravel the mystery and lead us to the guilty regardless of when or how the DNA was collected, how much incentive the police had to "find" new evidence or the absence of sensible and reliable corroboration. He's far from alone.

Here's some reading you may find interesting. I'll try to post a few more links tomorrow:

Dealing with DNA in Court : its use and misuse - Public Defenders Office : Lawlink NSW

Is DNA evidence sufficiently reliable for it to be used as the sole evidence against a defendant?

When an unadulterated suspect sample is compared with an unadulterated crime scene stain it is highly unlikely that there is error. However, because such errors have been known to occur it would not be wise to presume that the DNA evidence is infallible. There are a number or reasons why it is simply not possible to say that a match between a crime scene stain and a suspect proves he or she is the offender. These include:

· ....

· The potential for human error.· The potential for contamination of samples. For an excellent review of why courts cannot be complacent about contamination, see K Edwards, “Ten things about DNA contamination that lawyers should know” (2005) 29 A Crim LJ 71. Most police forensic officers are well-trained professionals but not all exhibits are collected by trained professionals. Sometimes pressure of work or cost-cutting can lead to unacceptable shortcuts being taken. Examples of improper techniques that can lead to contamination of DNA samples include, improper bagging and storage of exhibits, for example, bundling them all in a bag or back of the car, transfer of DNA by fingerprint brushes, tweezers, or gloves which were used on more than one item.· Handling errors because of the conditions in which the DNA is kept or stored. It is surprising how many samples, numbers and barcodes do not match with numbers and barcodes recorded in notebooks or exhibit books. DNA profiles can be obtained from such small amounts of body tissue or fluid, it is often hard to avoid cross-contamination of samples. The most recent example arose in R v Murdoch in the NT Supreme Court (the Falconio case) where DNA from the chief of the laboratory doing the testing was found on a crime scene sample...· There is always a possibility of tampering with the crime scene. This is not to impugn the police or Laboratory staff. Other criminals could have left the sample and it would be naïve to assume that all police can resist the temptation to plant evidence.· The suspect’s sample could have arrived at the crime scene for a number of innocent reasons — secondary transfer or prior contact with the scene or exhibit._______

For all the reasons above and all the reasons Chris describes and Judge Hellman boldly articulated, the DNA evidence in this case is a problem.

Chris, you said that when it comes to Sollecito's dna in the bra clasp, even if it's his, it doesn't prove he has done anything wrong. There's a problem with that. Sollecito wasn't Meredith's boy friend,or brother, or living there, Meredith wasn't a prostitute who sold sex for him,and he had no business fondeling her bra,he didn't do her laundry, those are only innocent explanations. There's no other reason for his dna to go right in to the spot of her bra from where it was cut with knife.If he had fondeled it, he would have said so to save him from murder charges.Where is the other murderer's dna then, if Sollecito is innocent? How did the other cutter of bra cut it in half with knife without touching bra while cutting it? There must be a cutter's dna on it, unles he used gloves.Also your guestion, where are Sollecito's finger prints from M's wrists if he was holding her down? My answer: he could have sat on them, hold her down by her sleeves, or the prints didn't attach on her, or they were wiped, or wasn't even taken from her, or he used gloves. Does hand prints always stay on victim, it's my understanding that no, otherwise most murders would be solved easily by this.It seems you use wild imagination to defend them-there's ALWAYS an explanation, no matter what, but don't do the same to think criticly to show how easily they could have done it.Be critical both ways, that's the only way finding the truth, otherwise don't even bother.Also being intellectually HONEST is the second most important thing in finding the truth, you don't use either of these.

Did Guede fly through Filomena's window when he came in through it? Why CSI say the glass from smashed window was untouched, and had landed infront of window shields making it show that shields were closed at the moment the window was smashed from inside.No glass was found fallen outside of the house, no glass had been wiped off, or moved, but it was scattered under the window. It shows that nobody hadn't come through the window after it was smashed.The truth is indeed in the details:)Who is the only one who had a motive to stage a burglary in that particular house? There's only ONE person- like it not.

According to news reports, Guede was friends with the guys who lived downstairs and had expressed sexual interest in Knox and Kercher.

Since there was a sexual assault, if there was no sign of a break in, he would expect the cops to look very hard at everyone Kercher knew and particularly who had been sexually interested in her.

I don't know what Italy is like, but from what I read it's very likely they would take an especially hard look at the black guy.

And they certainly would take a hard look at the homeless guy, and the guy with no job, and the guy who'd been caught in a burglary a few weeks before.

So Guede had a strong reason to stage it if he had either been let in by Kercher, on some pretext like "Let me use the bathroom" or caught alone outside and forced to let Guede in.

Personally, I would favor let in voluntarily because some of her electronics were used in a normal way after she must have gotten home though of course things might have been normal at first then he attacked.

And one more quick comment, it seems Knox' DNA being where it was has very plausible innocent explanations. But if the system and the cops were honest and competent, Sollecito's does not. I don't at all believe this is what happened but Sollecito being involved, as "proved" by the his DNA on the bra clasp, does not implicate Knox at all, she could have been back at Sollecito's place asleep.

In response to Anon at 10:27 who assumes Sollecito's DNA could only be on bra clasp if he was part of an assault on Kercher --I hate to tell you, but it turns out when college kids go away from home, a lot of them do a lot of sexual experimenting. Kercher could have been making out with Sollecito. The fact he was "not her boyfriend" does not exclude that at all. If you are going to try to tell me "Meredith" was not like that, first of all, I don't buy it, because you didn't know Meredith Kercher, and second, the fact is, the girls who 'aren't like that" also do it.

Have you considered the possibility that the clasp was torn, as opposed to cut? The photo I saw of the bra suggests that the clasp was torn away from it. Sollecito’s lawyers argued that one would be unlikely to leave DNA on the clasp without also leaving it on the bra itself; I don’t disagree, but I would question any assumption that the clasp was ever touched during the assault. With respect to the evidence that should be there but is not, you suggested that Sollecito might have worn gloves. If Sollecito wore gloves to restrain Meredith, then how did he deposit DNA on the clasp?

Perhaps we should begin to draw a distinction between environmental DNA and DNA that arrives from secondary/tertiary transfer. I think that the door-to-glove-to clasp scenario is one of several plausible routes of DNA transfer, but I am not wedded to one theory. There are a large number of additional alleles to account for, especially in the YSTR profile. There had to be at bare minimum two more male contributors to the profile besides what is attributed to Sollecito, and some loci have 3 or 4 other contributors. Did all of these men murder Meredith?

Gallagher, perhaps it's gobbledygook because you don't understand this process? Perhaps also I'm not spending enough time linking enough stuff because I don't really remember the code for this program and thus I spend a lot of time 'proving I'm not a robot' just to get one post through. This is much easier at JREF where I'm familiar with the software or IIP where it's similar.

It appears to me just about everything you've said about Chris and his argument is wrong, but not through malice but a lack of understanding. You've read Dr. Balding's paper and his interview I assume? You seem to realize he said at the outset that he may well be profiling contamination right?

You'll note Dr. Balding also said you can go down below 50 RFUs to 25-30 and it's become common. That's what Professor Halkides is doing, he's showing you that when you do that you find even more evidence of individuals involved, something that wouldn't be apparent to Dr. Balding unless he viewed an electropherogram where those peaks had been labeled and called, or most especially in this instance because he never analyzed the Y-str results where it's obvious for the reason I posted above as Chris has patiently posted and cited.

Just to be sure, you do realize that the electropherogram will only show one allele at each loci for each 'number' (of repeats) no matter how many contributors with that 'number,' right? You can check that for yourself by looking at Meredith's reference profiles (the ones they took to compare findings with) and as Meredith has two repeats of '12' at CSF1PO only one peak is displayed in the reference profile, the one that showed up stronger. With the clasp you can see an example of that at D7S820, Meredith and Raffaele both have 8 and 11 repeats, there's only one 8 and one 11, (Meredith's obviously) that 10 there is one of the other contributors, but as you can see there's not two '8s' or 11s.'

It's kinda like a game of Keno, no matter how many players have a certain number, the main board (the electropherogram) is only going to show one number, the strongest, the others are 'masked.' So those extra peaks that Stefanoni ignored without doubt show additional contributors who share 'numbers' with Raffaele and Meredith and/or evidence of their presence could be found by lowering the threshold further as Chris Halkides has done and Dr. Balding pointed out was common these days in Britain. It's not like those alleles are all that would be seen when Meredith and Raffaele have 15, it doesn't work like that, and while it appears Raffaele is the largest of the minor contributors the difference is not that profound. Statistical analysis can be done on those contributors as well, I'd start by checking the ones we know were in the murder room or around it after the murder. The ones who contributed would end up with impressive-looking numbers as well, (because they did contribute) though at the same time Raffaele's (and Meredith's) would go down but that's simply a function of the methodology. The ones who didn't would get numbers not unlike what he got from Amanda.

I posted that video for a reason as it shows the bra at the discovery, then the clasp when found and that they'd obviously taken the mattress out, amongst other things. Here's my point: so they collected the bra...but didn't notice the clasp was still on the ground? How'd that happen? Was it perhaps hanging by a thread and by sticking it in the evidence bag it was dislodged and fell (presumably) to the ground and they didn't notice it? Did it get kicked somewhere out of sight? They did the rest of their work afterward, including removing the mattress and didn't notice it? When doing a 'last look' they couldn't see it, or didn't care? They seemed awfully happy to find it when they did, why was it so more important then than all the times they must have been missed it (or not cared) as they collected things in that room and finished their work? Where was the bra clasp then? Where was it the six weeks in the interim as it sat there, would you lay money there were no drafts in that house with a broken window (in Filomena's) and the door off Meredith's room?

What I wrote about contamination and how that video was received can be inferred from the relevant sections in C&V, (and a little googling) they spent a great deal of time on it, I didn't just pull it out of my ass. As for Mignini, well, you look into that and keep in mind how many people he's charged now and how ridiculous his theories are, he's a corrupt fanatic but he's a master of the game and knows how to 'prove' things in Italian Courts no matter how silly they are.

As for a 'lack of experts' you're mistaken on that and you've had a number of people referred to and cited from in this thread. In addition to the three from the FBI another professional forensic expert weighed in and wrote a book, his name is Ron Hendry and the book was just released, why don't you buy it?

There was no 'million-dollar' PR campaign, with all the legal and travel expenses for that rather normal family there'd be little budget for such an outrageous expense. However because the Knox and Mellas family went to a public relations firm when besieged by the international press, the PMF/TJMK crowd simply assumed that each and every person who did weigh in must have been part of an artificial PR effort when in fact they were just people like you and I who got interested and spoke out and added their expertise, which is the perfectly natural grassroots phenomena even more prevalent today through social media.

You can find them if you want, some have blogs, some you can find at the facebook pages as well, though I almost never go on that program because I dislike it: any program I can't figure out/can't remember how to make a paragraph break is not very compatible with my posting style!

However as this puzzle has already been solved (it's really not that tough to figure out) and there was a group of people I call 'bunnies' out there smearing and defaming anyone who came forward as some PR shill, not all of them are as interested in enduring that as you might imagine. Think of what it must be like to offer your expertise on a matter like this and then be the subject of ridicule throughout the ether, to have them questioning your integrity when you're telling the truth by people who just got their nonsense off some kooky website like TJMK or PMF who don't even understand much of what you're saying?

As you point out there's nothing earthshattering in Dr. Balding's paper. He just ran the Weight of Evidence numbers on Raffaele, my guess is C&V didn't because when you get caught cheating and hiding the data necessary to evaluate your work you don't get a number grade and an asterisk, you get a zero and an asterisk because you might use that number grade to deceive people. Some naturally assume that contamination is a rare event thus it's impossible for them to believe that DNA adhered didn't happen in the course of anything but what the prosecution is alleging.

What I'm saying is that clasp doesn't have any corroboration for it being evidence of Raffaele being involved in the murder, but there's all sorts of ways the contamination could have happened and probably did during the collection, handling and testing. What that bra clasp electropherogram probably shows is the record of that journey from the moment it was photographed right by the bra to 46 or so days later when it was finally 'collected.'

It's a sample of Meredith with a lot of 'environmental contamination' including Raffaele's DNA, and I'd love to see some more 'suspect centered analysis' of the other possible contributors that I named above and see those numbers run as well so we can put this result in context and not just cherry-pick it from a whole room filled with possible other contributors...and even more evidence of how contaminated that crime site was by the time they went back.

As for the polarization, there's only two possible outcomes in this case, either Raffaele and Amanda were involved, or they were not. With all the information available in this case and the number of experts who did weight in the cogent ought to be able to figure out one side or another has to be disastrously wrong about a lot of things.

This is one of them, simply giving a weight of evidence to contamination does not make it valid evidence or the contamination route less probable than the prosecution interpretation, and this case shows what can happen when things like chain of custody and disclosure are abused to this degree.

My inference to rational debate, or lack of, was with regards to the opposing camps - pro innocence and pro guilt, and their complete polarization. It was certainly not directed towards yourself. I would have thought that obvious. As for deflections and appeals to higher authorities, I don't know what you are talking about.

I asked you, politely, had you been aware that as Balding informed us - virtually no crime sample is free of extraneous DNA. It seemed strange, that as a scientist, you had not been aware of this. You did not reply and I respected that. I still do.

As for what defines environmental or extraneous DNA and the relevance to a crime sample, we would all like to know that. I'm sure any working forensics officer has that information and would be happy to oblige.

Go back to the beginning of the Cartwheels thread and note that it's Halides1 saying that and the bunnies telling him, Fulcannelli is the one I most recall, that there was none of that on the EDFs, he'd read them himself!

Incidentally, (and correct me if I'm wrong about your argument) if you think the bra clasp is not unique, that every sample has that many contributors from 'environmental contamination' then why if you were to go down that list on the knife blade wouldn't you get the same number of potential contributors? Meredith's peaks are basically all there is, even though she had to essentially count everything above noise level.

Interesting comment Mary. So I guess what you are saying is you would expect there to be more than one DNA sample of Mr. Sollecito if there is one?

But

1) they dont sample everything. So maybe there were. 2) there are allegations of a clean up. 3) dont you think the absence of Sollecito DNA elsewhere makes it hard to allege accidental contamination? You might still allege a conspiracy to frame him.

Sometimes people who believe Sollecito was not involved suggest that the contamination was caused by bringing objects into the flat from outside - i think his mop. Im not entirely familiar with this argument. You might want to elaborate on this as a means to explain the contamination.

Allegations of a clean-up can't overcome the lack of evidence of a clean-up. Also, it is vital to differentiate between how much of Sollecito's DNA the police sampled and how much of his DNA was actually present. As you said, "they don't sample everything" For example, Sollecito was known to have touched Meredith's door; therefore, some DNA must have been deposited there. If Sollecito washed his hands at the women's flat, then his DNA is on the towels.

Chris, I would be very grateful if you could clear something up for me.

I was of the impression (and I am grateful for being corrected in wrong) that touching an object was no guarantee of leaving behind DNA. That a) one would need to quite forceful to leave behind live cells. b) dead cells leave degraded DNA behind, and c) that one can distinguish between keratinized cells and other cells because the former yields little or no DNA. Im sure I must be wrong about one of these.

If touching an object was itself sufficient then it is surely odd that Guede did not leave his DNA behind in other rooms like the smaller bathroom where someone left a bloody footprint and appears to have washed Meredith's blood off them.

But like most issues in this trial, I suspect this is a burden of proof question.

If you argue that the possibility of contamination is sufficient, then any DNA evidence can be dismissed. Effectively no DNA evidence which places Sollecito at the scene would be of value because all of it might have arisen from contamination.

But if we can consider probabilities, I suggest we consider two competing hypothesis. a) Sollecito left DNA in the apartment but not in the room. This DNA was accidentally picked up by the Scientific police but did not contaminate ANY of the other samples. It only contaminated their test of the clasp. b) The DNA was on the clasp from the beginning. To my mind the simplest and most probable hypothesis is the second. He does not appear to have left DNA anywhere else that was tested.

Of course, this could just be a case of deliberate planting of evidence. I have nothing useful to say about this possibility.

Harry, you're right, I would expect there to be more than one sample, but that's not my point. My point is that no one rips a bra off and leaves only a few cells on a metal hook. If Raffaele handled the bra, then he left a realistic amount of DNA there in the first place. For that amount to have been removed from the non-hook portions of the bra by the time the clasp was "found" and tested, the clasp would have had to have been through the wringer. And there is your route to contamination, if you want one.

I myself don't hold to the contamination theory. It's too easy to fake test results in a lab. The defense shouldn't have to prove contamination; the prosecution should have to prove they actually tested the bra clasp as found.

I can't remember right now whether the clasp was cut from the bra. In any case, the clasp became separated from the bra after the perpetrator tried to pull it off (you can tell by how bent and distorted the hooks are).

We've had a lot of discussions about this in other venues. No, in this case, the metal clasp is actually one of the least likely places for skin cells to be caught. This was not an attack in which things were being done carefully.

Touching an object is not a guarantee, but it happens frequently (very roughly 50% of the time and dependent on the particulars). I don’t believe that a great deal of force is necessary, and rubbing is certainly not necessary; however, either could increase the amount of DNA transferred. One study used polypropylene (soft plastic) test tubes, and this study found that the last person to touch the object did not necessarily leave the most DNA. There are many factors that go into how much DNA is left: if someone has just washed his or her hands, they will deposit less DNA. Typically, rough objects collect more DNA than smooth ones. Some of the DNA that is transferred by touch is cell-free DNA (CNA). The subject of keratinization of cells is somewhat complex, but my understanding is that keratinized cells will eventually lose DNA because the integrity of the nucleus is lost and eventually the DNA degrades. However, it is an empirical fact that touching can leave DNA behind, and so there must be one or more sources of DNA. Sweat contains both epithelial cells and CNAs, and both have DNA. The article “Touch DNA. What is it? Where is it? How much can be found? And, how can it impact my case?” by Suzanna Ryan is a very good summary.

I suspect that some of Guede’s DNA went down the sink when he washed. We cannot be sure what the scientific police did or did not contaminate unless they release the negative controls in the form of electronic data files. It is also worth bearing in mind that contamination can be sporadic, as well as global, despite what the Court of Cassation may believe. One hypothesis is that the forensic police contaminated the clasp with a small amount of Raffaele’s DNA previously deposited on Meredith’s door. Another is that Rudy transferred Raffaele’s DNA from the towels to the clasp via secondary or tertiary transfer. The latter idea is plausible if one of the towels that Rudy transported had been used for hand washing. One wishes that the towels had been more carefully preserved.

The possibility of tampering with the evidence cannot be dismissed out of hand. Both the timing and the manner in which the clasp was collected raise questions. However, I would exclude the bra clasp as evidence on two grounds in any case. One, every piece of DNA evidence collected on 18 December should be excluded because DNA is supposed to be collected in a timely manner. Two, the forensic workers should have used disposable tweezers or a fresh pair of gloves. If one does not build into the system an incentive to adhere to reasonable standards, they will keep on doing the same sloppy work over and over again. Even people who believe that Knox and Sollecito are guilty should be up in arms over the way that the bra clasp was collected because sooner or later unchecked sloppy work will convict an innocent person.

Clothing can sometimes contain multiple profiles. The CAC News wrote, “It was several years later that a little-known paper was published by the FBI DNA unit (Stouder et al., 2001). The aim of this paper was to compare recovery and typeability of habitual wearer DNA using swabbing and scraping techniques. Using new or freshly laundered garments, and pressing into service their own employees, researchers found a surprisingly high number of mixed profiles, some identifiable, some not. (Figure 1)...Where there is a known single habitual wearer [of an item of clothing], that person tends to be detected as the major source of DNA on a garment; minor profiles may also be detected from individuals with whom the habitual wearer has had close contact as well as from unknown sources." A footnote to Table 1 of the original paper by Stouder states, "Although the spouse and children cannot be excluded as potential contributors to these mixtures, they cannot account for all the non-wearer's DNA present."http://www.fbi.gov/about-us/lab/forensic-science-communications/fsc/oct2001/stouder.htm

Part 1Well, Prof Balding pretty much answers what we already knew. That RS DNA may well be on the bra clasp metal hook. Although he fails to take into account the UN-certified, unequipped, and unqualified status of the lab and technicians used to examine this LTN sample in 2007. (Plus the known lies used by the lab tech about her science in her testimony in the different courts.)

This is a rather brief and certainly incomplete interview with Balding IMHO.

Perhaps today there are protocols and standards that allow for LTN samples to be used in court as the only piece of evidence in 2013. But was that so in 2007? Does he consider or ignore missing special equipment and handling and qualifications?

Professor Balding examined the data provided to him which is the same as what was provided to the defense...which was and remains something quite incomplete...a picture in essence produced by Stefanoni who demands that we accept and trust her work. Prof Balding is not asked if he has concerns about these two 2 samples.

And while the question about negative controls was asked by Chris who parsed it as a yes or no question to keep it objective...I think a follow up question was in order.

Prof Balding. Would it be troubling for you if the electronic data files and control samples runs were being withheld from the defense by the prosecution?

Would you be concerned at all if no controls were run on these two particular LTN samples? Or that the same person who prepared the data you reviewed also was caught in court giving false statements (several hundred picograms); Oh, I forgot that we did run TMB tests on all the luminal hits...I always do control runs and I have never had a lab contamination just for starters about highly questionable trustworthiness and honesty of the tech and her boss who just so happened to work as a consultant for the prosecution.

The knife is at least as important as the metal hook. There didn't seem to be any quantification issues with the clasp sample and therefore there is zero excuse for non-repeatability of this test on this sample.

It's like the dog rusted my metal hook excuse...sure, OK if this was a single example of incompetence! I wish he would have spoken about the so called "double DNA knife".

Sure this was held to a rather narrow science only review of the one sample...but I wonder if Balding would have opinions about the strange coincidences of non repeatable tests for both critical LTN samples? Is he concerned at all about the lack of caution or any special equipment not used by this one lab?

Did he actually watch the bra clasp collection video? I can clearly see when one guy touches the metal hook as another holds it...not troubled by that at all?

As Kaosium mentioned ...was he simply looking at this from a statistical standpoint for this one sample.

Part 2He fails to take into account that there is no evidence of RS that bolster this hook sample. How did Raffaele touch this hook during the attack yet leave no other evidence of that at all? No footprint or shoe prints where he stood when he touched this hook. And nothing for Amanda when she was suppose to have cut MK with the un-matching knife either.

As a scientist he is asked about the metal hook DNA only. But if he actually reviewed the collection video and has no issues with that then I wonder how reliable his opinion is.

Is he concerned about the non-standard approach to the testing of a too low, too low, too low...(cont for 7 times) quantification of the only other critical evidence? DO the lies about said sample bother him? How about no repeatability of this sample as well? No problem?

Scientifically sound data? Enough to lock away defendants for life?

I am bothered a bit by the fact that this professor, much like Stefanoni, had the two defendant reference profiles in front of him to examine as he reviewed this work...he should be alarmed by that as well.

Nothing against the Prof at all...I just happen to think this interview fails to take into account the other circumstantial evidence that seems to indicate no involvement of either of these two defendants.

So the Professor thinks RS DNA is likely found on this metal hook. But he has failed to suggest how it got there without leaving one other bit of evidence. Did RS hover over the blood covered floor as he satisfied his urges and what was the evidence of these the "urges" again? Manga? A turnip?

How does the good professor feel about the multiple returns to the cottage for more DNA evidence? What does he think about items left there the first few times? Bloody outer jacket... sleeves turned inside out, bloody shoes and socks, the purse!

But no matter...if Prof Balding examined the complete scientific data and can proclaim these two or maybe just the one LTN samples to be safe and reliable and sound then I suggest he review the texts a bit further and also reexamine the complete data taking into account what he is missing (denied) as well as what he is supplied.

Is this Professor experienced in Forensic investigation or is he a teacher like Alan Dershowitz?

The Bra Clasp evidence is moot. Amanda was intimate with Rafaelle, but went to her cottage to do laundry and clean up. I am just supplying one in many obvious scenarios...Since Amanda would be the transport vehicle of whoever's DNA, and went to the cottage to use the same bathroom, same laundry, why wouldn't she also deposit trace DNA from this third peson? I am just saying, for every so called "logic" argument against these two individuals, there are 100 alternate also logical arguments the opposite.

I've got a point about the police planting Sollecito's DNA which I and other posters hinted at in other posts, by asking Chris if DNA evidence has ever indicated a police frame.

Now I will try to lay it out more directly:

It seems to me at some point, depending on the crime scene, and how carefully police and forensic scientists examine the evidence, and how good the technology is, the presence of the suspect's DNA in only one spot would be very strong evidence of a police frame, ie, going to the jail, taking Sollecito's drinking cup, and takin it over to the crime scene and rubbing it on the bra clasp.

What's crucial is the "Only ONE spot" part.

If you have Sollecito's DNA ONLY on the bra clasp, when it should be in the bathroom, on the towels, on the bed sheets, on Kercher's clothes, and so forth, then you have to suspect it was planted.

I don't know much about these issues. One would think some or all of those other objects would have been removed six weeks after the crime. I read the bed itself was completely removed. One would hope so.

If they checked very carefully on all those other objects, (one would hope so, but who knows with this bunch?) and did not find anything, I think it's very strong evidence of a plant.

It may be that Knox' DNA was not found in the bedroom because they did not have a crooked cop in the woman's jail to collect it, whereas someone loyal to Mignini was working in the men's jail.

I very much respect and appreciate this blog and the thoughtful and very informative comments and discussion here, but I think while everyone gets in touch with science very well here there is an unrealistical presumption of good faith on the part of the cops, who have been proven to arrest and jail people who they had to know beyond any doubt were innocent. The Italian reporter, corroborator with Douglas Preston, was jailed for murder charges for criticizing Mignini in the Monster of Florence case.And speaking of science, prominent seismologists have now been given a 6 year prison sentence for saying they thought a major earthquake was unlikely shortly before one happened and killed a lot of people. The question of police framing in this case should be looked at in purely statistical/probability terms, that is with NO presumption whatever of any honesty or good faith. But unfortunately the data may not exist to do that.

I repeat myself again: IF there had been an innocent reason for Raffaelle's dna to land on Meredith's bra clasp, he WOULD HAVE SAID SO! He was asked, he spent 4 years in prison thinking hard to find a way getting away from murder charges and evidence shown against him in court, so I believe he and his clever lawyer would have come up with any kind of real, or invented story to explain it. He would have said so in court if he had a reason for it!He's no idiot!He hasn't given any innocent reason!Case closed.

I agree, Anonymous. The only thing Dr. Balding or any scientist can do at this point is evaluate the data that were provided by the police. We have seen example after example of the Perugian police acting in bad faith and lying outright. Now they have destroyed the clasp so it can't be tested again? How convenient. That alone should keep it out of court.

After everything they have done, there is no reason to believe them when they claim they did not collect the clasp the first time around, or that they stumbled across it six weeks later. They set up the second search on camera only after they knew they were losing the shoeprints as the single bit of physical evidence they had against Raffaele.

There also is no reason to believe they ever tested the bra clasp. There IS reason to believe they are hiding something. As Chris wrote, "Without negative controls or electronic data files, the work presented in this paper is incomplete, and it is not worthwhile as evidence in a court of law."

I also Googled the guestion: "can murderer's dna stay on victim's skin?" And after reading some results, the answer was: not almost ever. Decomposing of body, sweat, etc. affects that if somebody holds my hands down, and I die, his dna most likely can't be found on my skin later by police. Sometimes police can find it, most of the times not.Why don't we all just let the police do their job, and we can concentrate on owr own jobs instead? The idea that "you just know everything better than csi" is starting really be boring.

"The Postal Police testified that they showed up at the cottage 20 minutes before Raffaele called the emergency number, but the video from the camera across the street proved they arrived after he made the call.

"The Postal Police testified that they never set foot inside Meredith's room, but two witnesses testified that they did.

"An unnamed police source told Richard Owen of the UK Times that they found receipts showing the purchase of bleach on the morning after the murder, and he went with the story, but no such receipts exist.

"They lied on December 18 when they told the media that the book Amanda claimed to have been reading at Raffaele's apartment was found instead at the cottage. But the book to which she was referring really was at Raffaele's apartment, and they knew it. It was captured on police video taken more than a month earlier.

"The police say they treated Amanda well during her interrogation, but they don't have a recording of that interrogation, even though it was required by law, they made recordings of all the other witness statements, and they secretly recorded Amanda and Raffaele when they were alone together.

"Comodi lied about the call made "before anything happened" when she questioned Amanda. She said Amanda called her mother at noon, but in fact, Amanda did not make that call until 12:47, after she had spoken to Raffaele, after she had discovered the broken window, and after she had spoken to Filomena four times.

"Rinaldi lied about the size of Guede's foot to create the false impression that it was too big to have made the print on the mat.

"Stefanoni lied about performing a second blood test on the luminol footprints, saying that no such test was performed. Later, under pressure from defense lawyers, she provided documents showing that a second test was performed, and it was negative for blood in every case.

"Stefanoni also lied when she testified that she changed gloves every time she handled a new sample. Raffaele's lawyers were able to prove from the video that she was lying.

If touching an object was itself sufficient then it is surely odd that Guede did not leave his DNA behind in other rooms like the smaller bathroom where someone left a bloody footprint and appears to have washed Meredith's blood off them.

This is an interesting point, by all accounts Rudy had blood on his hands and feet. He left a bloody handprint and shoeprints all over the scene. His own story incorporates him getting blood on his hands and clothes, including an explanation for the blood on the wall in which he claimed he was trying to write something. He claims in his own story that he went into the bathroom to get the towels.

So how come they didn't find Rudy Guede's DNA in the bathroom? It could be happenstance, however remember the prosecution was trying to pretend the partial bathmat stain was Raffaele's, finding Rudy Guede's DNA in the bathroom would be problematical for that assertion.

Keep in mind what they did for the luminol hits, which was also a part of the second trip to the crime scene. They did TMB tests on the luminol hits they got which were negative, but they would (initially) tell the court they never did those tests. Then when they had to turn over more of their records it was found they had indeed done TMB tests that were negative on the luminol hits.

They were initially alleging those luminol hits were 'bloody footprints' caused by Raffaele and Amanda having their feet stained with Meredith's blood. However when it was discovered they'd done the tests and they were negative, they then claimed they were footprints which had been diluted to be between the detection thresholds of TMB and luminol. If that was actually their thinking at the time, why didn't they do a confirmatory test like they did on other samples? If that was actually diluted blood then what was the source of whatever substance it was diluted with in the murder room where they allege they originated?

There isn't one, those were luminol hits they got on a hallway which tested negative for blood that they ignored/hid the falsifier for and tried to claim in court were 'bloody footprints' and then when the TMB tests were revealed came up with a highly unlikely explanation for it which doesn't fit whatsoever into the logic of the event. The only thing the luminol hits prove is there was no clean-up in that hall.

If they are going to hide something as devastating to their claim as a negative blood test, why wouldn't they do so with DNA hits that would do the same? It's not like they ever fully disclosed all the tests they did or even the results of the ones they did use in court. Regarding the clasp Stefanoni didn't just 'miss' the extra peaks not in stutter position and over 15%, she tried to pretend they weren't alleles when she had to know better.

If you argue that the possibility of contamination is sufficient, then any DNA evidence can be dismissed. Effectively no DNA evidence which places Sollecito at the scene would be of value because all of it might have arisen from contamination.

There's two forensic investigations here, nothing from the second one should be considered anything but contaminated, and incidentally that's where the most specious of their evidence claims comes from. That hallway they laid down luminol in and did the TMB tests they hid/'forgot' about was freely walked through and used for their equipment after they processed Rudy's barely visible shoeprints. Watch the crime scene videos and see how many were walking through there and how they used it to store equipment.

From a forensic standpoint when they went back six weeks later they weren't finding evidence of the murder, that was not the last event at that scene, they were finding evidence of the previous investigation on top of what was left of the integrity of the murder site. That was the last event that took place, not the murder. That some transfer might have taken place is hardly surprising being as they weren't especially careful and had gone in and out of that room directly through where Raffaele had tried to break down that door and went down to look into the keyhole.

It's not like there's any mystery as to who killed Meredith Kercher, there's plenty of evidence that was Rudy Guede who fled to Germany after leaving traces all over the scene. What this is about is the fact the police in Perugia had arrested three people previously on the basis of evidence that turned out to be entirely mistaken and coincidental and came up with a bizarro theory that the forensics didn't bear out. They went back to that contaminated crime scene because they didn't have evidence of the three person theory they'd grabbed headlines with, and even with that even the prosecution's forensic experts (as per Massei) had to testify there was nothing about the murder that required more than one attacker.

Incidentally, I don't understand what you mean by the bra clasp being the only thing contaminated. How would you know if it was just a slight transfer from something to the bra clasp or the bra clasp came into contact with something from the floor perhaps by someone walking through the doorway? How would you determine whether someone else, such as the luminol hit in Filomena's room wasn't also contamination transferred by those technicians has they walked through the house on the floors where Meredith and Amanda lived?

Anon. at 1:25 PM, I suggest you read an earlier entry here on DNA in strangulation. Even in simulated strangulation, which I suspect is much less prone to transfer DNA than actual strangulation, DNA transfer happens frequently. I am not saying that detecting such transfer is a sure thing. However, it is interesting that Guede’s DNA was found on Meredith’s jacket.

You wrote, “Essentially, the problem here, as the court sees it, is what is to stop defence lawyers advancing contamination claims in any murder case.” This is exactly 180 degrees wrong, as can be seen by asking the following question: “How would a defense team go about their job under the conditions set forth by the ISC?”

You wrote, “What interested me most about your interview, was Balding's laying to rest of the old contamination theory by several other males. He informs us that this environmental DNA is completely normal and routine. Frankly, it's shocking that such nonsense talk about the additional males was allowed to continue unchecked. Were you, as a scientist aware of this?” When I first pointed out that even household dust had DNA over three years ago, I was met with derision by a number of PG-commenters. We are DNA-shedding machines. The problem is how to distinguish between environmental DNA and other DNA. In addition, if there is additional DNA unrelated to a crime that is on an item of evidence, then it is contaminated by one prominent definition of the term.

You wrote, “True, the court speaks about the unproven hypothesis of contamination, and Novelli said the origin or path of contamination must be demonstrated, and that makes sense.” No, it does not. Even in some of the most carefully studied examples of DNA contamination, there are times when the exact route of contamination could not be determined. I would say it is more probable than not that the moment of contamination remains elusive, even when experts are given access to all of the relevant data (which was not the case here).

You wrote, “I don't think you can be serious about how a knife can be cleaned of blood but not DNA - if there is DNA on the blade, that speaks for itself.” There is no reason whatsoever to assume that Meredith’s DNA was ever on the blade—maybe it was, but maybe it was not. Bleach is very effective at destroying DNA. Detergent would dissolve the cell membrane of any mammalian cell, and the DNA would then be at the mercy of enzymes known as nucleases. I have already quoted two forensic experts on this matter; therefore, yes, I am quite serious.

You wrote, “There is really nothing new in all of this, as I said before, what struck me most, was the laying to rest by Balding of several male contributors to the bra clasp DNA.” Dr. Balding did not address environmental DNA in his paper, or a referee might have objected. What is beyond dispute is that there is more than one contributor to the YSTR profile, as I have discussed upthread. Even using the most conservative threshold, there are two additional profiles. Given that Stefanoni used a threshold of well below 50 RFU with respect to the knife profile, there is surely no reason not to go below 50 RFU here.

You wrote, “I think that teaches us that we should solicit the views of those people directly involved within the various professions concerning this case - real forensic crime scene officers, real police detectives.” As I discussed upthread, I did seek out one former police officer’s view, and he said that the scene was contaminated.

Gallagher, You wrote, “What would I accept as proof of contamination" - well thank God we are on your forum, otherwise I might have been asked for a timeline!” This is a non-answer, yet there are examples of contamination from around the world. How can a defense attorney make a case that contamination has happened if the court cannot articulate what it would accept as proof?

In response to Kasosium you wrote, “So any sample with Knox's or Sollecito's DNA you term anomalous?” The Rome lab was not even certified for standard DNA forensics, let alone LCN forensics, yet the knife profile was clearly in the low template range. The bra clasp was a mixture, and the work of Dror and Hampikian has shown that subjectivity may come into play when DNA mixtures are analyzed.

You wrote, “You also want to give the impression that Kercher's DNA on the blade is somehow imaginary because it is low template, when , in fact, there is confirmation from leading experts.” This is a misstatement. Most people agree that Kercher’s profile was observed (I do). The problem is that low template work requires even higher standards than regular DNA profiling to avoid contamination, and Stefanoni seemed unaware of some of them, even as late as 2011.

You wrote, “My point regarding the video was basically that if people record themselves you can generally rest assured they will not do much wrong. You know as well as I do that you could video brain surgery and there would still be room for criticism.” This is not a helpful analogy. Most of us would not be able to spot an error in surgery, but the errors made by the FP are obvious to anyone who reads about evidence handling protocols. There is no good reason not to change gloves. In addition, you did not squarely respond to my point, which is that if there is no punishment for doing it wrong, there is no reason to expect they will do it right, video or not.

You wrote, “You had the courage to publish, yet as a scientist, you must have been aware that the extra male contributors were from environmental DNA or that the likelihood existed.” One, every attempt to distinguish between environmental DNA and other DNA will run afoul of the axiom that the presence of DNA rarely gives information on the time or manner of its deposition. However, suppose that we are willing to violate this rule. Can we come up with a difference between environmental DNA and other DNA, whether or not it has experimental support? Let’s consider the autosomal profile of the clasp first. One could argue that Raffaele’s profile is about two-thirds complete but the additional contributor(s) produced a much less complete profile. OK, so maybe we can assume that environmental DNA leaves incomplete profiles. Now let us consider the YSTR profile of the clasp. Even using a conservative cutoff and ignoring possible stutters, there is at least one peak that is not Raffaele’s in at least 5 loci, and in one locus there are two such peaks (I am leaving DY385 out of the analysis entirely—it has an anomalous property). In other words, one could construct a pretty good partial profile. In response one could say, OK, maybe environmental DNA always gives small peaks (this is false, but let’s see where it leads); therefore, we can ignore the other male contributors as being “environmental.” Two problems: one, the difference in peak size is within fourfold, and two, some of the unassigned peaks in the autosomal profile are about as large as Raffaele’s peaks. Moreover, Raffaele’s peaks are much smaller than Meredith’s peaks (about eightfold). If we try to use peak height differences as our criterion, we would be on relatively safer ground classifying both the unknown peaks and Raffaele’s peaks in the autosomal profile as being environmental than trying to differentiate between the unknown peaks and Raffaele’s peaks. To sum up, I don’t think one can use the profiles themselves to differentiate between what is environmental DNA and what is not.(to be continued)

Part 2You wrote, “I asked you, politely, had you been aware that as Balding informed us - virtually no crime sample is free of extraneous DNA. It seemed strange, that as a scientist, you had not been aware of this. As for what defines environmental or extraneous DNA and the relevance to a crime sample, we would all like to know that. I'm sure any working forensics officer has that information and would be happy to oblige.” I think it is important to differentiate between drop-in peaks, which are often seen in true LCN DNA profiles, and environmental DNA, which is still an incompletely understood phenomenon. A 2010 review by Van Oorshot and colleagues (one previously cited at this blog) stated, “The first point can be viewed as the level of background DNA present under normal circumstances [88,201,202]. The second may occur as a result of innocent interactions by unrelated individuals. Although these two contamination points, termed adventitious transfer, cannot be strictly controlled, there are methods to account for and to minimize the impact of such contamination. These approaches/methods include…” They use the word “minimize,” as opposed to eliminate, and they go on to mention the very study on DNA and dust that I discussed and that Conti and Vecchiotti later cited as the authors indicated the need for more such work.

Your final comment is another non-answer, and it is also is among the most bewildering comments I have encountered in some time. One, Van Oorshot and colleagues made it clear that further study is called for. Two, if one asked a forensic technician at a lab to classify peaks in an egram into probative versus environmental, it would be putting them in to an occasion of sin, to borrow a term from Roman Catholicism. They would be tempted to put any peak that was not the suspect’s or the victim’s into that convenient category. That is why one needs an objective standard. Yet, crafting an objective standard is fraught with difficulties, as I indicated in part 1 of this comment.

"The guilter bloggers are creepy because you know in their heart of hearts they want to hurt innocent people, but there are always creeps, always have been."

You dont think there is something a little creepy about lots of americans deciding that a foreign police force are wrong to accuse a white American girl, and that the lone criminal was an black Italian teenager.

What makes me think all the people asserting Amanda's innocence are white? Would any black person who believes Amanda is innocent please contradict me.

Let me return to the issue of environmental DNA. In their 2010 article in Investigative Genetics, Van Oorshot and colleagues suggested six ways to minimize the impact of environmental contamination: “6. where possible obtain a profile of the background DNA from an area immediately adjacent to the target area to assist profile interpretation.” This is known as a substrate control, and Conti and Vecchiotti also indicated that a substrate control should have been done with respect to the bra clasp collection (as I mentioned upthread). Therefore, Conti and Vecchiotti are within the mainstream of forensic thinking in their suggestion.

In response to the question of DNA contamination Dr. Balding writes, "The only worry would be if somehow DNA from Sollecito was brought into the room and deposited on item 165B. I don't know enough about what happened to say if that was likely but I'd guess that people walking in and out of the room etc would be unlikely to do that."

To begin, the forensic science literature is full of published research which refutes this uninformed assumption. It would be helpful if Dr. Balding were to review this work before making such a comment. More specifically to this case, this comment begs the question, “how did the other male DNA get onto the bra clasp, Dr. Balding?” According the Balding’s assumption this event also would also appear to be ‘unlikely’, but clearly it happened. Therefore, it is useful to look further at how DNA contamination could occur.

Here, based on his comment above, I presume Balding is unaware of the ubiquitous presence of human DNA in common household dust. I further presume he is unaware that Raffaele was present outside the door of Meredith's room on the day after the Meredith was killed, trying to get into her room to find out if she was there; working extensively with the door knob and pushing against the door. I further presume that Balding has no idea how much cellular debris could be released by such activities. Obviously, Balding has no idea how people walking in and out of the room could spread such cellular material. (My personal observation is that household dust is quite light and somewhat sticky and easily moves from place to place.) In addition, DNA on the door knob or the door itself could also have been transferred into the room. Would people entering the room be equally unlikely to do so without touching the door knob or the door itself?

One obvious rhetorical question here would be, if such things were not important, than why do forensic Standards of Evidence state that evidence be collected as promptly after an event as possible? Why does it matter?

"Standard 2.1 Collecting DNA evidence from a crime scene or other location

(a) Whenever a serious crime appears to have been committed and there is reason to believe that DNA evidence relevant to the crime may be present at the crime scene or other location, that evidence should be collected promptly."

http://www.americanbar.org/publications ... e.html#2.1

It is also worth noting that the bra clasp had been moved around on the floor of the room and videos indicate it had become visibly contaminated with dust. This is exactly the sort of contamination event that the Standards of Evidence are designed to limit.

Balding also responds to a question about the improper forensic techniques followed by the forensic scientists in collecting the bra clasp by restating the key issue, “the only concern is if any of this could have transferred DNA from Sollecito onto item 165B”. T

I guess, Balding said it well in his own words when he stated, "I don't know enough about what happened to say if that was likely but I'd guess that people walking in and out of the room etc. would be unlikely to do that."

I would emphasize, Balding doesn't know enough about the relevant phenomena and the scientific literature about this subject to have an informed opinion, so what he imagines is likely or not is of little significance.

I believe Dr. Balding does know enough about the relevant phenomena and the scientific literature to have an informed opinion on the data he was presented with. Personally, I agree with his take on the unlikelihood of accidental contamination during the process of collection. The chances are beyond remote that the investigators tracked DNA around and accidentally happened to transfer a bit of Raffaele's onto the bra clasp and nowhere else.

The information Dr. Balding doesn't have is about the kind of people we are dealing with here. They lie, they cheat and they break laws, routinely. Foul play in the lab is likely, even probable.

I was the anonymous poster who made the comment that the guilters are creepy and want to kind of apologize for it, as I think Chris is interested in DNA and it's his blog and comments like that may make the blog discussion deteriorate in a way he does not want, and I am really grateful to him for his fascinating informative blog. But to be honest, though I feel like I need to understand DNA more, my interest in this Amanda Knox phenomenon was originally more about why people have the world view that kind of assumes guilt and sticks to it, and get so angry about the issue. I've been a victim of significant misconduct by prosecutors in the US, though not sent to prison on a frame, it's a long story that did not involve disputed DNA or anything like that but the point is, some people seem to have no skepticism of the authorities. You see this on Nancy Grace but in most of the cases she covers you don't have a complete nutcase like Mignini. But it does not seem to matter, some people stick with the original accusation no matter what comes up to discredit it. I see this kind of mindset as a threat to democracy itself when carried far enough. But certainly supporting abuses within the criminal justice system. Sorry for long winded comment. As far as Amanda Knox goes, and Sollectito, though it looks like they are innocent and I feel compassion for them on that basis, for me this is about Mignini and the Italian legal system, but more than that, making US citizens like myself realize our system has serious problems and is sliding towards ever increasing power in the hands of prosecutors which of course some will abuse. So, in reply to Anon -- black people should be MUCH more concerned about the Bill of Rights than anyone else, because of a tradition of abuses by authorities against them. And in keeping with that, they should opposed all continued prosecutions where the prosecutor has been discredited, here or abroad, such as Mignini has.

You appear to be making the point that the extraneous DNA, which Balding informs us is completely routine, has in fact been deposited directly or indirectly by a third party, hence the clasp is contaminated and useless as evidence. These are your personal opinions. They are the views that anyone from the pro innocence camp would be expected to have, just as the pro guilt agree whole heartedly with Balding.

But that was not the question here. I asked you, had you been aware as Balding informs us, that extraneous or environmental DNA is found on virtually every crime sample - not your personal interpretation of the data. In simple terms, a statement such as - the clasp was found to have the DNA of several other contributors - may be factually correct. It is also highly misleading, since it does not inform us that the extraneous DNA is completely routine. See the difference? See the slight of hand?

You are partially wrong about Professor Balding. At least some of the pro-guilt camp agrees with his conclusion that Sollecito’s DNA is present on the clasp, but they cannot force themselves to admit that Knox’s is not. Your statement about contamination is misleading. Van Oorshot and colleagues wrote, “From a theoretical perspective, any DNA deposit that is not immediately relevant to the crime being investigated can be viewed as contamination.” Thus the clasp is contaminated by their definition, not my opinion.

I addressed many comments and questions to you in the past week,including but not limited to the very issue of environmental contamination. Apparently, you did not understand my distinction between drop-in and environmental contamination (or many of the other things that I wrote in the last two days), or you would not have written your second paragraph. You would be helping yourself and your credibility if you read them, thought about them, and asked questions about them in ways that directly addressed the issues that I raised. In an earlier comment you wrote, “My inference to rational debate, or lack of, was with regards to the opposing camps - pro innocence and pro guilt, and their complete polarization.” This implies an equivalence between the two camps that simply does not exist. To see just one small corner of the lack of equivalence consider the following thought experiment. Suppose that you went to one of the pro-guilt sites and either failed to answer the questions that were directed to you or questioned the integrity of the host. How long would you last before you were thanked for stopping by?

I believe Dr. Balding does know enough about the relevant phenomena and the scientific literature to have an informed opinion on the data he was presented with. Personally, I agree with his take on the unlikelihood of accidental contamination during the process of collection. The chances are beyond remote that the investigators tracked DNA around and accidentally happened to transfer a bit of Raffaele's onto the bra clasp and nowhere else.

I must ask Mary H, how many PCR's have you performed? "the chances are beyond remote...?" seriously, based on what? I can see Mary H that you have not read the literature.

Mary H provides a prime example of an unitiated observer who presumes to comment on an art where they have no expertise and no particular insight. To put it bluntly, Mary H, you don't know what you are talking about.

As a practicing Molecular Biologist who does PCR all the time, I have seen 'PCR contamination' happen and can confirm that this is a well documented real world problem in PCR labs. It is intrinsic to the PCR process itself. This is why there are formal standards for forensic labs about appropriate procedures that need to be followed.

It is a demonstration of ignorance/arrogance to attempt to gloss over such scientific realities.

Chris, I did not know Knox' DNA was not found in Kercher's bedroom. Seems like a good reason to modify one's theories about Knox being involved. I don't want to slow down this discussion but now I am curious, is there any actual evidence against Knox that does not have an innocent explanation?

Yom, how many cubic millimeters of material do you think there are in a 3 meter x 3 meter x 3 meter bedroom? I bet it comes to a very big number, like in the kajillions. (Where is that PMF math lady when we need her?)

To calculate the chances of the investigators accidentally transferring 1 cubic millimeter of any random person's DNA onto any one specific piece of material in the room and nowhere else, all you have to do is form a ratio of 1 cubic millimeter to the kajillions of available cubic millimeters of material in a 3 m. x 3 m. x 3 m. room.

I bet the denominator comes out to be so much bigger than the numerator that it does produce a chance that can accurately be described as "remote," for example: 1/100 kajillions.

To calculate the chances of investigators depositing one SPECIFIC person's DNA onto any one specific location in the room, you have to calculate a ratio of the chances of them picking up one specific person's DNA out of all the possible DNA they could pick up, and then factor that ratio into the chances from the first ratio.

I am going to guess that those calculations will get you to a ratio that make your chances even more remote. (I feel kind of like saying, "Of all the gin joints in all the towns in all the world, she walks into mine.")

To reach the firm conclusion that one cubic millimeter of Raffaele’s DNA was accidentally deposited onto one cubic millimeter of the bra clasp, all you have to do is perform the calculations above, see how remote the chances are, and then suspend reality as we know it.

If I am wrong, feel free to tell me how the chances should be calculated.

Anon. at 2:23 AM, There is some mixed DNA in the shared bathroom and in Filomena's bedroom. However, I have dealt with mixed DNA in an earlier entry here, and I am strongly inclined to ascribe this to the fact that they lived in the same house and used the same bedroom. The collection technique of the forensic police would also be prone to mixing DNA samples. Therefore, there is no evidence against Knox that does not have an innocent explanation. The bra clasp is the only decent physical evidence against Sollecito, and it is highly flawed, as I have indicated. The bathmat print should not be used as evidence against either Sollecito or Guede; it was made on a soft surface with diluted blood, and it lacks identifying details.

Also -- Mary H. -- though I agree with you that likely the bra clasp DNA, if it existed at all, was planted, I think you've got the numbers way exaggerated on the chance of an accidental contamination. You asked for people to tell you how you were wrong -- well, for one thing, just think about tracking mud into a room -- probably not a perfect analogy and Chris knows this much better -- but you don't track mud onto the walls or ceiling of a room, you track it on the floor, where the bra clasp had been allowed to sit for six weeks, and apparently stepped on at least once. And because things fall, you can't look at volume, you have to look at area of the floor. And don't forget the cops and prosecutor say the DNA is evidence not contamination.

I don't mean to monopolize and know nothing about the lab workers but I would point out, in the Duke Lacrosse case, a DNA lab the prosecutor used deliberately hid results which were viewed as exonerating the accused. Apparently, playing lawyerly games, they put the raw data in an extremely large sheaf of papers given to the defense, but not the basic conclusion there was a lot of DNA on the accuser from other men. So, DNA lab managers, like everyone else, can be convinced to put out misleading information. I don't know but maybe Chris has thoughts about the lab work?

I agree with both of you. There are multiple routes by which Sollecito's DNA might have arrived innocently. On the other hand, evidence tampering is known to have occurred many times in the U.S. alone (the country with which I am most familiar). Therefore, it is not unreasonable to suspect tampering in a high-profile case in which the defendants are already in custody (among other factors).

But for the purposes of clarity allow me to summarise what I took from thee Balding interview.

Dr. Balding can confirm that according to reasonable standards of proof, the autosomal DNA on the clasp was Sollecito's. He cannot comment on how that DNA got there. He does note that one can expect some background level of third party DNA to be present - which is true in the case.

I also took from it (less certain here) that the height of the peaks suggested the Sollecitos DNA was of a different quality (higher peaks although still low) than the victim, and the other third party DNA. Specifically, Sollecitos "signals" of were substantially lower amplification than MKs and but substantially higher than the third party "contamination".

The impression I get is that this places Sollecito in the flat.

However there is an argument that it may not categorically place him in the room because the police may have inadvertently tracked his DNA into the room.

There is also an argument that it is odd that there is no other DNA evidence of RS's presence.

So I ask the following questions.

1) How many instances of RG's DNA do we have in the crime scene?

2) How many other occasions of Sollecito's DNA are there in the apartment? If it is contamination the police should have been able to find his DNA elsewhere.

3) If it is contamination, how likely is it that it would be restricted to the evidence point - the clasp?

4) The small bathroom was obviously used by someone who had access to the body. Why can we only find AKs DNA in that bathroom? Particularly in areas where we find MKs blood. Surely we should expect to find RGs DNA there?

I think Balding has moved the ball forward by helping to explain that it is reasonable to assume that RS's DNA is on the clasp. He says nothing about how that DNA got there, but that it would have to have been transported there - deliberately or inadvertently.

So we are left with the question about what are the odds that that sample arrived in the room from outside of it.

To my mind the probability of that happening inadvertently is no greater than 5%. The probability of that occurring deliberately is impossible for me to gauge.

Ask your self this guestion: Since we know Meredith's blood was found in toilet and in Filomena's room, (mixed with Amanda's dna) WHO ELSE dropped those blood drops and stains in there? Was it Meredith? Everything points that not being her since she died in her room, and there's no marks her leaving the room after stabbed. So SOMEBODY brought her blood in those rooms. Who was it? Was it Guede? Why are there no dna or anything from Guede in those blood drops if it was him? If it was him, how come his dna isn't in those, but Amanda's IS? Maybe it just WAS Amanda?-I know what you did last november-

Can someone clear this up for me? I see pictures online of the bra clasp that seem to be dated February 11. Yet I keep reading about the bra clasp being sampled six weeks after the murder. November 2 to mid February is more than 3 months. Also, if anyone knows, when was a warrant issued for Guede? When did they get the handprints and match them with his?

Anonymous at 10:10 AM, you are absolutely right. There is a much higher likelihood of contamination for objects the investigators had contact with. Thank you for the correction.

Harry at 11:38, great summary and great questions. This is why I posted the references to the police and prosecution lies. Given their previous misconduct, it is not hard to determine their level of credibility. Add that to the withholding of the raw data and the destruction of the bra clasp.

Questioning your integrity? Look, I asked you a simple question. I also offered my congratulations for having the courage to publish Balding, since the interview was so prejudicial to your position. I made it clear that your personal motivations were none of my business and would respect a non response.

As for any questions you posed me, I can only recall - what would I accept as proof of contamination - I trust you were being flippant. Your other comments regarded your personal interpretation of the DNA data and outlandish remarks about the scientific police and the Rome laboratory. As you have reminded me, you are the host, and so in the best mannerly way, I can only say that if you want to believe this stuff, that's up to you.

But you are absolutely right concerning the various sites and their tolerances. It's okay to claim Knox is a murderer and it's okay to say she is Mother Theresa, but ask a few critical questions and you're out.

1. There are at least four instances of his DNA. Some of it is YSTR, and some of it is autosomal. Judge Micheli got this wrong (I have looked over some of the egrams).

2. There is only the cigarette butt, but as I have said before, one should not equate the number of places that his DNA was found with the number of places that his DNA existed in the apartment.

3. Contamination can be global or sporadic. Have you watched the FP handle the clasp? That is why I keep coming back to the need to change gloves. If the bra were cut (as I believe it was, based on the photograph I saw at JREFF), then I don’t see why anyone would need to have touched it in the assault.

4. If I swabbed your bathroom, would I find your DNA? If so, then if I placed blood droplets of person X in your bathroom, I would have mixed DNA between you and person X. Here is still another example in which substrate controls would have helped. The FP could have sampled areas close to the blood but away from it. They did not do so. How exhaustively did the FP sample the bathroom? What did Guede do that would deposit DNA in the small bathroom? If he bled and used the towels to slow the bleeding, the towels would have his DNA. Unfortunately the towels were stored in such a way that allowed microorganisms to grow, to the best of my understanding.

Many people, including Conti and Vecchiotti, think that Raffaele’s DNA is on the clasp. Therefore, I don’t find Professor Balding’s conclusions very surprising. It is long past time for ILE to release the electronic data files. That would allow more and better analysis, and a better appraisal of the possibility of contamination.

Anon. at 10:16, There is no doubt that Ms. Stefanoni put out misleading information. She vastly overstated the amount of DNA from the knife profile, and she was very misleading with respect to the fact that TMB blood testing had been done and had turned up negative.

One important difference between this case and the Duke lacrosse case is that North Carolina has open discovery, whereas in Italy discovery is present in theory but not in practice, at least as far as this case is concerned. A commenter named Diocletian at Injustice Anywhere is trying to figure out just what Stefanoni did, but he is hampered by the lack of release Micheli and Massei, especially, facilitated.

Gallagher, if I'm understanding you correctly the basis of your question is wrong. If you're arguing that the extra alleles found on the bra clasp are nothing out of the ordinary, how do you explain this? Here's a listing of the e-grams Diocletus of JREF and IIP did recently:

All those above listed as 'single profile' don't have enough 'environmental contamination' to make another profile, they just may have a stray peak, such as the one on the knife blade E-gram. They make up 90% of the e-grams Stefanoni produced in this case.

On the other hand the bra clasp has not only Raffaele and Meredith, it has enough evidence of other contributors to place the minimum number of males (outside Raffaele) contributing to the claps at 2 and perhaps even more, plus there's the possibility of another female. Once that main 'keno card' (the electropherogram) starts to fill up, each additional contributor is less likely to 'add' alleles, being as a previous contributor may have the same number of repeats at that locus and it 'masks' any weaker ones.

Just because some environmental contamination is not unusual doesn't mean the plethora of it on the clasp is dismissible as the same, in fact if you think on the nature of what that 'environmental contamination' actually is, it would figure that a clasp vulnerable to being contaminated by its environment to the extent the bra clasp was would show a lot more of it--as it very well does.

For anyone curious, Lumumba's result is probably his reference profile and the ones showing Raffaele and Amanda mixes were found at Raffaele's because they were more or less living together most of the week before the murder. It doesn't suggest Raffaele killed Amanda, nor the other way around, it's simply a result of the fact they were living together.

So we have a four to one ratio of observations of Guede's DNA in the room compared to observations of Sollecito's DNA.

1) Its important to consider symmetry in arguments. If we allege the possibility of contamination in one case we should equally consider it in the other.

So this provides some support to the notion that we can be more "sure" of Guede's presence in the room but indications Sollecito's presence are more likely to have been caused by contamination.

2) Its true that we cannot rule out contamination but we need to consider the likelihood as well. If there was a lot of Sollecito's DNA in the environment then contamination is much more likely. If they touched areas contaminated by Sollecito then why did such areas not show on the test? (of course they might not have tested the correct areas).

Ironically some forms of "contamination might not be considered proof of innocence". Contamination from WITHIN the murder scene would also prove guilt. My understanding of the Italian Court of Cassations reasoning is that you cannot assume contamination unless you can indicate a viable path. Thats not the same as ruling it out - a possible is not a probable. But to assume contamination you would need to show evidence of some DNA outside the room. Its unfortunate for Sollecito that no tests outside the room showed the presence of his DNA. If we accept this logic arnt we left with a substantial positive probability of his presence in the room? Not a certainty but life isnt rich in certainties?

It boils down to a Bayesian assessment of null and alternative hypothesis. What is the probability of his DNA turning up on the clasp if he wasnt in the room. And what is the probability of his DNA turning up on the clasp if he was in the room?

As usual I do not consider the possibility of police malfeasance. I have no evidence. I dont rule it out.

3) If you swabbed my bathroom you would definitely find my DNA. If a third party was murdered in my bathroom and the blood washed from the murderer, you would find my DNA mixed with theirs in areas where my DNA had come to rest and had not been cleaned away. Like under the plug or in the u-bend. However, if you tested only areas where there were tiny droplets of blood, it would be highly suggestive of my involvement if my DNA happened to be co-mingled with a mixture of water and blood in each of these places.

Of course I would like a control. If you find my DNA in the traces of blood, can you find it in areas with no blood traces? If you can then its clearly of less value that you find two DNA samples in the blood traces. Without the control I can see why you question the value of the evidence. However we know that someone associated with Meredith's killing entered that bathroom with absolute certainty. We have searched for their DNA. And apparently we have found only Amanda Knox's. If anyone finds the absence of Sollecito's DNA except for one location (clasp) odd, then they should find the absence of Guede's DNA from the small bathroom odd as well.

I found Balding's comments helpful because I had a long debate with someone about whether or not the CV tests had identified Sollecito. So for me this cleared something up.

One last opinion. The poor performance of the Italian scientific police does not indicate either guilt or innocence. All it does is create some uncertainty around the forensic evidence. The degree of uncertainty is open to interpretation. I certainly dont consider this open and shut guilt. But I certainly don't think innocence is obvious either. Things should have been done better but I dont think this makes conviction impossible.

Indeed I suspect all doubts could potentially be laid to rest if the knife is tested again using appropriate LCN techniques.

You wrote, “If they touched areas contaminated by Sollecito then why did such areas not show on the test?” One, the FP seemed more interested in testing blood than most other things (understandable, but a little narrow in my view). Two, if the route of transfer were from the door to gloves, to the clasp, who knows what they touched right afterwards.

You wrote, “My understanding of the Italian Court of Cassations reasoning is that you cannot assume contamination unless you can indicate a viable path…Its unfortunate for Sollecito that no tests outside the room showed the presence of his DNA.” The cigarette butt had his DNA, and his fingerprints were on the door. Therefore, his DNA was present outside of the room. We have identified several viable paths (via the gloves, via the towels, etc.), plus one plausibility argument: clothing is known to have DNA from unknown individuals on it (cited upthread). It is reasonable to suppose that some of the DNA that is found on clothing arrives via secondary or tertiary transfer.

You wrote, “And what is the probability of his DNA turning up on the clasp if he was in the room?” Not all that large. The bra was torn, not cut, and I don’t see a need for even the true culprit to have touched it. Rudy’s DNA is on the bra, BTW.

You wrote, “However, if you tested only areas where there were tiny droplets of blood, it would be highly suggestive of my involvement if my DNA happened to be co-mingled with a mixture of water and blood in each of these places. Of course I would like a control. If you find my DNA in the traces of blood, can you find it in areas with no blood traces? If you can then its clearly of less value that you find two DNA samples in the blood traces.” With respect you are being hasty. I would hazard a guess that brushing one’s teeth deposits more DNA than washing one’s hands, with or without blood (cheek cells are a good source of DNA). Moreover, you seem to be ignoring the towels that could not be properly tested. Guede says he was bleeding, and we know he had cuts when he was arrested. The towels would have been the most likely place to find his DNA. Therefore, I have never found the lack of Guede’s DNA in the bathroom surprising. And in response to a positive result from a substrate control, I would not say ‘less value;’ I would say ‘no value whatsoever.’

You wrote, “Indeed I suspect all doubts could potentially be laid to rest if the knife is tested again using appropriate LCN techniques.” I strongly disagree, but it would take too much space to explain my reasons here. There is a thread at IA called “Math on Trial” that could be consulted for my opinions.

You wrote, “As for any questions you posed me, I can only recall - what would I accept as proof of contamination - I trust you were being flippant. Your other comments regarded your personal interpretation of the DNA data and outlandish remarks about the scientific police and the Rome laboratory.” The question was quite serious. I suggest you give it more thought. Can you explain which remarks you thought were outlandish and why?

I live in the UK. The clasp is in Italy. You, I understand are somewhere in the US. I do not have any documentation or data pertaining to the clasp, nor am I much interested in the finer intricacies of the subject, nor have I a particular wish to broaden my understanding. That's why most people are happy to say " let's leave it to the experts". Now certainly, not all experts will agree with each other, which I think is the problem you are encountering here. May I suggest that you contact Balding again. Or, if for any reason you dislike or disagree with Balding, you may feel he is not reasonable or impartial, you could try someone else. But I would certainly not be the person to advise on these issues, though I must say, I am flattered you asked.

I wanted to formally apologize to Mary H for some rude posts I made upthread. I am new to this forum, and didn't understand the thread that I was jumping into. I have strong, well formed opinions about this case. It just goes to show me how important it is to be respectful, and to actually think before venting frustrations about this case. Mary H, sorry again.

Gallagher -- I can't speak for Chris but if you did not want to learn about the DNA why ask all these questions? Why challenge an opinion on the grounds of science without looking at the science in enough detail to really understand it?

I am also wondering if you believe Sollecito's DNA on Kercher's clothes implicate Knox in any crime? I ask this because seems like Knox could have been at Sollecito's place asleep and Sollecito at Knox' murdering Kercher.

I know this is blog is maybe more about DNA than Amanda Knox but I did wish to point out many things don't seem to make sense.

It seems like the easiest thing in the world would have been for Knox and Sollecito to make a plan to implicate Guede without implicating themselves.

How? There were several days in between the murder and Knox' so called confession.

In that time, is it really likely two university students would not be able to come up with "I (or we) came home and Guede was there talking to Meredith. When I left he was still there".

With that simple statement, which in no way implicates them in any crime, Sollecito and Knox point the cops right at Guede, whose DNA they know will be found on Kercher, if they had been part of the murder. And the scarcity of their DNA at the scene at least proves if involved they had to have cleaned up because of awareness of DNA. One can not reasonably claim they did not know about DNA or did not think about it and yet did such a good job of cleaning the scene.

I have posed this question to believers in their guilt and the only answer has been Guede would then accuse them of taking part. This does not seem a logical objection. Guede would most likely deny everything, then admit sex with Kercher, but accusing Knox or Sollecito necessarily implicates him in the murder or at least a cover up afterwards. Eventually with DNA against him he might accuse them, but no rational person would expect him to be believed, since they had no motive to murder Kercher and all the evidence points to Guede. For the same reason, Knox accusing Lumumba makes no sense. She would know the DNA would not match Lumumba and her accusation would be disproven very fast. It would gain her nothing, so it would have made far more sense to deny all knowledge, beg off from the interrogation, then leave the country. Knox' story makes much more sense than the cops or prosecutors

Your answer indicates that you have misinterpreted my question, and by a considerable distance. Therefore, let me explain. I have in the past sought out help from world-recognized experts in the specific area of the science of DNA contamination, such as Professors Krane and Thompson. If you read some of the other entries here, you will find (and perhaps be grateful for) their thoughts. But my question was not about the forensics of contamination, it was about the legal issues surrounding contamination. If you had attempted to answer the question from the point of view of a defense lawyer, you would have been on the right track. Indeed, I also asked you, “How would a defense team go about their job [of defending a client when there is DNA evidence] under the conditions set forth by the ISC?” It is still a good question, and it is still unanswered.

Please try to understand. Perhaps we have taken off on the wrong foot here. I asked you a simple question - were you aware, as Balding informs us, that there is virtually no crime sample that is free of extraneous or environmental DNA. You have not replied directly to the question, but seem to prefer to provide your interpretations of this extraneous DNA instead. And that's fine. I do not have any problem with that. Perhaps you think Balding is completely wrong, and you could be right, I don't know. I posed the question, as I have already explained, because as a scientist it seemed strange that you were not familiar with this topic. You have, in return, posed me a question regarding DNA contamination and now on some associated legal issues regarding the ISC. Chris, I am not a lawyer. Why on earth would you pose such questions?

I have not asked a series of questions, just one simple query to Chris. No, I have no particular wish to learn about DNA - it is a very esoteric subject that is best left to the experts. It also bores the crap out of me. I have not challenged any scientific opinion, nor would I be in a position to do so, and really don't know what you are talking about in that regard.

I have no idea whether Sollecito's DNA could implicate Knox. But my basic gut feeling or intuition is that they did not kill anyone. The evidence tells another story, and that is why the case fascinates us so much.

You wrote, “You have, in return, posed me a question regarding DNA contamination and now on some associated legal issues regarding the ISC. Chris, I am not a lawyer. Why on earth would you pose such questions?” You misunderstood me. I gave you some examples of questions that you did not answer to point out that in a civil exchange of ideas, one answers, as well as asks, questions. To take another example, I am still waiting to hear which of my statements was “outlandish.”

However, the other questions I asked are still good questions for anyone trying to evaluate the section of the Court of Cassation’s motivations document that deals with DNA.

Initially you wrote, “What interested me most about your interview, was Balding's laying to rest of the old contamination theory by several other males. He informs us that this environmental DNA is completely normal and routine. Frankly, it's shocking that such nonsense talk about the additional males was allowed to continue unchecked. Were you, as a scientist aware of this?” Later you wrote, “You had the courage to publish, yet as a scientist, you must have been aware that the extra male contributors were from environmental DNA or that the likelihood existed.” And you wrote, “I asked you, politely, had you been aware that as Balding informed us - virtually no crime sample is free of extraneous DNA. It seemed strange, that as a scientist, you had not been aware of this.” Still later you wrote, “I asked you, had you been aware as Balding informs us, that extraneous or environmental DNA is found on virtually every crime sample.” And finally, “were you aware, as Balding informs us, that there is virtually no crime sample that is free of extraneous or environmental DNA.” There are some differences among the statements.

I took great care to answer this question last weekend, but it appears that you did not understand what I was saying. I will try to explain it differently. Not every electropherogram has drop-in peaks (a loose definition of a drop-in is a peak that shows up unexpectedly), but drop-in peaks are somewhat more common in LCN DNA. It is a stretch to claim that every drop-in is environmental in origin, unless substrate controls are performed. Other than the clasp only Rep. 177 in this case comes to mind as having a decent number of unexplained peaks. Most of the other egrams I have seen are pretty clean. In other words, the number of unknown peaks varies quite a bit from one sample to the next.

It is one thing to claim that every sample has environmental DNA, but it is going quite a bit further to claim that one can tell which peak is from an environmental source and which one is relevant to the crime (possibly because it arrived from primary transfer). I explained at some length that a criterion that might differentiate peaks in the autosomal profile would fail in the YSTR profile and vice versa. What truly would be nonsensical is to claim that Sollecito’s YSTR profile is meaningful with respect to the crime but the other DNA is not. Dr. Balding did not make that claim in his article, but your first statement essentially does. (to be continued)

Moreover, LCN profiles have some special issues with respect to peak heights. A DNA forensic scientist whom I consulted wrote, “To a large extent, peak height is correlated with the amount of template DNA but LCN approaches go out of their way to mask or remove indications of problems (e.g. by inflating peak heights and removing baseline noise) in a way that can make them quite misleading. It wouldn't be wise to give a high school football player morphine to mask the pain associated with a twisted ankle -- that pain is sending an important signal to the athlete that should be giving them a sense of the severity of the injury and how to prevent further aggravating it. If low peaks from an LCN approach are being carefully considered they should be only in the context of knowing that most if not all of those warning signs have been removed.” Sollecito’s profile on the clasp is in the low template region.

What would truly be a grave mistake would be granting forensic technicians the power to declare some peaks as extraneous on the basis of experience. It would be a little like allowing them to declare that something is blood on the basis of the appearance of a luminol reaction. Fortunately, forensic scientists know that subjectivity can creep into both DNA profiling and the interpretation of presumptive tests for blood and are finding ways to make their work more objective.

You wrote, “No, I have no particular wish to learn about DNA - it is a very esoteric subject that is best left to the experts. It also bores the crap out of me. I have not challenged any scientific opinion, nor would I be in a position to do so, and really don't know what you are talking about in that regard.” Your statement is false. Previously you wrote, “I don't think you can be serious about how a knife can be cleaned of blood but not DNA - if there is DNA on the blade, that speaks for itself.” Thus, you did challenge Dr. Elizabeth Johnson and Professor Gregory Hampikian.

Nobody still haven't answered my question: WHo ELSE brought Meredith's blood inside Filomena's room, and toilet after her death? We know Meredith didn't, since she died in her room. Somebody dropped her blood drops in F's room and toilet, WHO and HOW? Where is that OTHER (than Amanda's ) dna mixed with those blood drops, if you believe Amanda is innocent and her dna came from previously messing the place? Did Guede, why is his bloody foot steps going straight out, and where is his dna from the blood? Did M's blood fly alone to F's room/toilet? Answer this and you are genius!"I still know what you did last October"

Anonymous, The spots in Filomena's room have never been described as looking like drops. I have heard them called amorphous. They are luminol-positive but TMB-negative. I would say that there is only an outside chance that they are blood. Moreover, this evidence was collected after the FP had stepped in Meredith's dried blood and moved her mattress out of her bedroom. Meredith's DNA would have been spread around in this operation.

Guede's DNA might be on the towel that was stored improperly. Guede might have stepped in the blood on his return to the bedroom after beeing in the bathroom. His footsteps fade out (meaning that it is difficult to said what he did after that point; therefore, drawing the conclusion that you do is twice unwarranted.

It is beyond logic how anyone could have found either Knox or Solicito guilty. Too many people these days believe media accounts are reliabele, where many believe everything they read. This case is no different than any other case where people should be innocent before proven guilty. That didnt happen. They were convicted in the jury of public opinion long before the trial started. A crazy story entailing sexuakl encounters/drugs and murder captured the public and was so off the wall it was believed. The pictures published in the newspaper and social media were crime scene photos taken after luminol had been applied which lit up every protein on the wall (tooth paste, cleaning supplies, cells, and spills... which were lit up red and were used by the media and published where the pics apeared and made Knox look like a liar as she had claimed that there were a few droplets of blood... The pics made it lok like the walls were covered in blood and from that picture forward, Knox lost all credibility prior to the trial. The proof that these 2 were guilty before innocent is that the most simple reasonable doubt should have been applied at the get go. This simple question to one, would be how in the world could these 2 have been involved in any way of a brutal murder that left prints footpirnts dna pof Guede, where zero were found from the other 2. This simple question has ben ovrlooked and it the question that should offer reasonable doubt to anyone, and it should also be proof that if people are not considered innocent until prven guilty, they will be unfairly convicted where reasonabkle doubt should have been enough to allow them to walk. Getting caught up in DNA where most of us havent got a clue or the ability to understand with any type of certainty is enough to distract and create more hype where regular logic could have been implemented with basics. Again, how could these 2 have been in that blood bath and not left one ounce of evidence. Again, the bra clasp was proven by video to have been contaminated as it was moved in the 46 days and on account of that, it should be enough to consider contamination as well as not the proper standars to have been tested in the first place. The knife DNA is also enough to have been disregared as it was not blood dna that was ever alleged to be on the knife and to think that Knox brought a knife from Solicitos apartment, and then brought it back to his house washed it, and put it away is too much to believe.. it isnt logical. What also isnt logical is to think any one of these 2 could have lived for 20 and 27 years without ever being violent, and then all of a sudden having the desire to inflict unspeakable violence agaisnt another human being let alone a freind is too mucg to even consider. Promiscuity, doesnt equal violence/hatred and carnal sin. There is no evidence to prove that (historical) marijuana use made either one of them violent. The chances that on a freak occaision that a person did become violent on a drug that never gave them that side affect would in fact make 2 people who had never been violent all of a sudden become violent and both decide to throw their lives away doesnt make any sesnce of rational. This story should be an eye opener to society by showing how easy wrongful convictions are and that these 2 could have been anyones loved one.

Looks like Sollecito is hiding in Dominican Republic. He has also changed his alibi again. I think it's about sixth time. Somebody went to his facebook page and asked him about how did Meredith's blood end up on his knife. Raffaele said this time: I lied when I said that she was in my house and we cooked ogether and that he pricked Meredith's hand and that's how it went on his knife. Now he says he lied, and made up the whole story. And that it never happened.Ha ha ha!This guy is something else!

The metal bra claps are coated in a plasticised substance that could easily be electrically charged when friction or other movments are made. something that is charged in this manner and moved around the crime scene could easily pick up dust dandre and other air-born objects and would also aid it transference.

DNA should be held up to a scientific standard, just like all other evidence provided at trial. Most evidence is not contested and stipulated to by both the defence and prosecution. The evidentuary value if contested by either party should it be called into quastion, should be excluded from submission until the evidence can be examined to assertain its probative value. As soon as the DNA evidence was contested by the Defence to witch there was resonable cause to doubt the the validity of the evidence there should have been an evidenturay hearing to generate a final opinion on the value of the evidence in question. To just accept contested DNA evidence as un-refutable even under the objection of council without epert examination is a fatal flaw. If the evidence is admitted without meeting the standard then this is surely a contention on appeal. The singlar assertion that DNA is infoulable is false, and the burdon of all evidence meeting avidentuary standards is by default placed on the party submitting the evidence, therfor if the prosecution submits DNA evidence that is challenged by the defence to be contaminated, it is upto the prosecution to prove that the DNA meets the proper level. The defence never has the burdon of proof. the prosecution has burdon of proving their case beyond a reasonable doubt whic include proving the evidence meets the proper scientific and evidentuary standards.

What everyone spin when I make the following statement, the will dis-regard it as being silly without persuing its meaning:

"Amanda and Rafeale could not have commited the murder of Meridith Kercher as their DNA was found in the appartment rented by Rafeale on the day after the young British student was found slain at her apartment".

Balding may be a brilliant scientist, but he can't see the forest for the trees when he claims that he can't grok how people merely walking in and out of the bedroom could transfer Raffaele's DNA to the clasp (technically, a RED HERRING fallacy).

Since Raffaele had tried breaking down Meredith's door (but failed), once that door was opened into the bedroom, Raffaele's DNA was likely already in Meredith's bedroom since it was on that door!

So then, did a technician touch that door before fondling the clasp?

At the end of Tape-1 they were seen touching that door, then around 30 minutes into Tape-2 they found the clasp, and then passed that around with their dirty gloves (didn't they have disposable tweezers?)

Evidence processed with new LT-DNA methods must also include flawless collection of the evidence, and the collection of that clasp was botched start to finish.

I doubt if Balding would calmly accept his own daughter being prosecuted using evidence collected like that!

Common sense dictates that Raffaele wasn't in that room during the murder when the only trace of him was found on that tiny bra-clasp, but not on the rest of the bra, or anywhere else in the room.

About Me

I am a biochemist who specializes in the chemical modification of proteins and the synthesis of potential enzyme inhibitors. I am particularly interested in the chemistry of phosphorus and sulfur as it can be applied to biochemical problems.